Seminar archive | Fermilab Cosmic Physics Center

Event date	Title	Speakers	Host	Summary	Links
Sept. 16, 2013, 2:30 pm US/Central	CDMSlite: A Search for Light WIMPs			The CDMS-low-ionization-threshold-experiment was designed to measure low-energy recoils from Weakly Interacting Massive Particles of mass < 10 GeV. This experiment uses voltage-assisted Luke-Neganov amplification of the ionization-energy deposited by particle interactions, which allows us to probe for light WIMP scatters. In this talk I will describe the physics behind CDMSlite and present science results from... More »
Sept. 23, 2013, 2:30 pm US/Central	Searching for Satellite Galaxies of the Milky Way in the Dark Energy Survey			During the past decade, wide-field optical surveys have brought to light a population of low-luminosity and highly dark-matter-dominated galaxies in the Local Group, which were discovered by their individually resolved stars. These systems have provided new targets to explore the processes which suppress star formation in low-mass dark matter halos, and to constrain the nature... More »
Sept. 30, 2013, 2:30 pm US/Central	Dark matter and flavor			I will discuss aspects of dark matter that dominantly couples to third generation quarks, including LHC signatures. I will also discuss one realization of a model of “top-flavored” dark matter that arises from supersymmetry with minimal flavor violation. Notes: 1405
Oct. 2, 2013, 2:30 pm US/Central	Fermi Bubbles under Dark Matter Scrutiny			The quest for Dark Matter signals in the gamma-ray sky is one of the most intriguing and exciting challenges in astrophysics. In this talk I will use Fermi Bubble photon spectrum to study the signal of Dark Matter. By exploring various setups for the full-sky analysis we achieve stable residual gamma ray spectrum, which can... More »
Oct. 7, 2013, 2:30 pm US/Central	Applied Astronomy: Optical Studies of Space Debris at Geosynchronous Orbit			The majority of artificial objects in Earth orbit are non-functional: inactive satellites, spent rocket boosters, and parts of spacecraft resulting from collisions and fragmentation events. This population of orbital debris is increasing with time, and represents a collision risk to active spacecraft. Studying the debris population at geosynchronous orbit (GEO, period = 23h56m) is a... More »
Oct. 14, 2013, 2:30 pm US/Central	Constraining Dark Matter Models using Fermi-LAT Gamma Ray Observations of the Galactic Center			Using Fermi Large Area Telescope (LAT) gamma ray observations, several independent groups have found excess extended gamma ray emission at the Galactic Center. It has been hypothesized that the excess emission may be due to dark matter. However, there are significant uncertainties in the diffuse Galactic background. We reevaluated the data accounting for the spectral... More »
Oct. 21, 2013, 2:30 pm US/Central	Interferometers for Cosmic Microwave Background Polarization Measurements			Measurement of B-type cosmic microwave background (CMB) polarization is a major goal in cosmology. Its achievement will require instruments with unprecedented control of systematic errors. I will discuss the development of QUBIC, a CMB polarization experiment combining aspects of classical imaging instruments and interferometers, which is currently under development. I will also present results of... More »
Oct. 28, 2013, 2:30 pm US/Central	The Evolution of Galaxy Clustering as a Function of Luminosity and Color			I present measurements of the luminosity and color-dependence of galaxy clustering over the past eight billion years in the PRIsm MUlti-object Survey (PRIMUS). I quantify how the scale-dependent clustering amplitude increases with increasing luminosity and redder color, with relatively small errors over large volumes (9 sq. deg. of sky). I find that red galaxies have... More »
Nov. 4, 2013, 2:30 pm US/Central	Dark Matter in a Hidden Sector			A new force connecting the standard model with a hidden sector can arise naturally in various theories of physics beyond the standard model. In particular, light extra U(1) gauge bosons, so called hidden photons, are a theoretically well motivated candidate and could act as mediator of the interaction with dark matter particles in the hidden... More »
Nov. 11, 2013, 2:00 pm US/Central	Cosmic Sound, Near and Far			The coupling of baryons and photons by Thomson scattering in the early universe leads to a rich structure in the power spectra of the cosmic microwave background photons and the matter. The study of the former has revolutionized cosmology and allowed precise measurement of a host of important cosmological parameters. The study of the latter... More »
Nov. 18, 2013, 2:30 pm US/Central	The South Pole Telescope and the Millimeter Sky			The South Pole Telescope along with, the Herschel Space Observatory, and the recently commissioned Atacama Large Millimeter Array (ALMA) have opened a window to the millimeter (mm) sky and revealed a unique and unprecedented view of the Universe. I will present an overview of the rich scientific questions which are currently being addressed by studying... More »
Nov. 21, 2013, 12:00 pm US/Central	Inflationary Models after Planck			An unprecedented opportunity to constrain the inflationary theory is provided by the current flow of high accuracy astrophysical data, among which are the Cosmic Microwave Background measurements by the Planck satellite. This is however a challenging project given the size of the inflationary landscape which contains hundreds of different scenarios. In this talk I will... More »
Nov. 25, 2013, 2:30 pm US/Central	Challenges of Relic Neutrino Detection and the Status of the PTOLEMY Experiment			A new experiment called PTOLEMY (Princeton Tritium Observatory for Light, Early-Universe, Massive-Neutrino Yield) is under development at the Princeton Plasma Physics Laboratory with the goal of challenging one of the most fundamental predictions of the Big Bang – the present-day existence of relic neutrinos produced less than one second after the Big Bang. With the... More »
Dec. 2, 2013, 2:30 pm US/Central	The Quest for Primordial Non-Gaussianity			Vanilla single-field, slow-roll inflationary theory predicts that primordial fluctuations in the universe were nearly Gaussian random, although some very well-motivated models specifically predict observably large non-Gaussianity. Measurements of primordial non-Gaussianity therefore represent a rare window into the physics moments after the Big Bang. I first review the history of measurements of non-Gaussianity from the cosmic... More »
Dec. 9, 2013, 2:30 pm US/Central	Re-discovering the Radio Transient Sky			The Astronomy & Astrophysics Decadal Survey identified time domain astronomy as one of the emerging frontier areas, potentially leading to transformational discoveries. Observations at radio wavelengths have illustrated the potential of the time domain (or “transients”), most notably with the discovery of neutron stars as radio pulsars, a discovery later awarded a Nobel Prize. Since... More »
Dec. 16, 2013, 2:30 pm US/Central	News from the low-mass WIMP front			I’ll discuss some recent developments in direct searches for dark matter focusing on low-mass WIMPs, including LUX, CoGeNT and COUPP/PICO. Notes: 1357
Jan. 22, 2014, 3:00 pm US/Central	Weak Lensing Magnification and Large Scale Structure			Gravitational lensing, the deflection of photons by changes in gravitational potential, modifies the observed brightness and shape of galaxies that lie behind massive objects. In an astronomical survey, the detected number count density of sources and their apparent brightnesses will be modified by the magnification effects of gravitational lensing. By measuring these effects we can... More »
Jan. 27, 2014, 2:30 pm US/Central	Cosmology Results from the Pan-STARRs Supernova Survey			The Pan-STARRs supernova survey has discovered one of the largest samples of Type Ia supernovae. Measurements of the distances to these supernovae allow us to probe some of the most fundamental questions about the properties of the universe like what is dark energy. When combining measurements from various astrophysical probes, we find interesting tension with... More »
Feb. 3, 2014, 2:30 pm US/Central	Some New Isocurvature Directions			I will discuss two unexplored parts of isocurvature parameter space. In one, the compensated isocurvature mode (a fluctuation in the cosmic baryon fraction), the usual linear theory observables are hidden, and the model unconstrained using familiar analyses. Instead, the hypothesis can be tested using the CMB trispectrum (put alternatively, using off-diagonal correlations). After developing the... More »
Feb. 10, 2014, 2:30 pm US/Central	The Fermilab Holometer: A Measurement of Planck Scale Quantum Geometry			We are developing an instrument to determine whether a newly predicted position uncertainty is compatible with experiment. The possibility that information in a system scales as its surface area rather than its volume – the holographic principle – motivates this prediction. The required position uncertainty, scaled by the entropy of black holes, is of a... More »
Feb. 17, 2014, 2:30 pm US/Central	Detecting Small Planets orbiting Small Stars			Thanks to Kepler, today we know that small stars often host Earth-size planets. Approximately half of all stars are low-mass M dwarfs, and at least half of these may have an Earth-size companion. This means it is likely that there are Earth-like planets within just a few parsecs of the Sun. Given the cool temperature,... More »
Feb. 24, 2014, 2:00 pm US/Central	Large-Scale Structure Formation with Massive Neutrinos			The lightest known massive particle in the Universe, the neutrino, is the focus of major terrestrial experiments. The physics of the neutrino sector is also being probed by ongoing and upcoming cosmological surveys. First postulated in 1930 by Wolfgang Pauli and discovered in 1956 by Cowan and Reines, the neutrino continues to surprise physicists. Introduced... More »
March 3, 2014, 2:00 pm US/Central	The high-energy cosmic-ray sky as seen by IceCube, IceTop and AMANDA			Cosmic rays with energies in the TeV-PeV range are believed to originate in astrophysical accelerators within our galaxy. During their propagation, cosmic rays are scattered by the Galactic magnetic field, a process that makes their arrival directions at Earth almost entirely isotropic. However, anisotropy with per-mille amplitude, or lower, should subsist in the cosmic-ray sky.... More »
March 10, 2014, 12:30 pm US/Central	The Characterization of the Gamma-Ray Signal from the Central Milky Way: A Compelling Case for Annihilating Dark Matter			In scenarios where dark matter particles can annihilate to produce standard model, the galactic center of the Milky Way is expected to provide the highest flux from dark matter in the sky. This has allowed galactic center observations to set extremely stringent limits on the parameters of the dark matter particle. Recently, we have worked... More »
March 10, 2014, 2:00 pm US/Central	DarkSide-50: Performance and results from the first atmospheric argon run			DarkSide-50 is the first physics detector of the DarkSide family, featuring a two-phase underground-argon Time Projection Chamber (50 kg sensitive mass) surrounded by an organic liquid scintillator veto (30 tonnes) and a muon water-Cherenkov detector (1000 tonnes). The two-phase detector is currently operating at Gran Sasso underground laboratory, fully shielded and filled with research grade... More »
March 17, 2014, 2:00 pm US/Central	An argument that the dark matter is axions			An argument is presented that the dark matter is axions, at least in part. It has three steps. First, axions behave differently from the other forms of cold dark matter because they form a rethermalizing Bose-Einstein condensate (BEC). Second, there is a tool to distinguish axion BEC from the other dark matter candidates on the... More »
March 31, 2014, 2:00 pm US/Central	Weak Gravitational Lensing of Galaxy Clusters			As the most massive bound objects in the universe, galaxy clusters are excellent probes of the underlying mass density field. The abundance of clusters as a function of mass and their spatial clustering directly constrain the overall mass density of the universe, as well as higher order properties such as the variance in the mass... More »
April 7, 2014, 12:30 pm US/Central	Gravitational Wave Detectors in Europe and the US			The detection of Gravitational waves is widely viewed as a “new window to the universe”. We report on the current effort of building the second generation of ground-based Gravitational-wave detectors in Europe and the US, as well as some related research. Detectors like Virgo (Italy), LIGO (US), and the smaller GEO600 (Germany) are technically complex,... More »
April 7, 2014, 2:00 pm US/Central	Weighing the Giants: Accurate Weak Lensing Mass Measurements for Cosmological Cluster Surveys			Surveys of galaxy clusters provide a sensitive probe of cosmology by measuring the evolution of the halo mass function. With a number of surveys at optical, millimeter, and X-ray wavelengths on-going or starting in the near futures, cluster count experiments will be one the most important cosmological probes over the next decade. However, none of... More »
April 21, 2014, 2:00 pm US/Central	Big B, Little B, What Begins with B? Bandits, B Modes, and Bispectrumese			One of the principal goals of early-Universe cosmology is detection of the characteristic curl, or “B mode,” signal in the cosmic microwave background (CMB) polarization. In this talk, I will discuss a new adaptive-survey strategy, inspired by the multi-armed-bandit problem in probability theory, to optimize the sensitivity of experiments to these B modes. I will... More »
May 5, 2014, 2:00 pm US/Central	Latest Results from the Cluster Lensing and Supernovae Survey with Hubble (CLASH)			The Cluster Lensing And Supernova survey with Hubble (CLASH) combines the gravitational lensing power of 25 massive clusters with the panchromatic imaging power of HST. It’s four primary scientific objectives are 1) map, with unprecedented accuracy, the distribution of dark matter in galaxy clusters and place constraints on the nature of the dark matter, 2)... More »
May 7, 2014, 3:00 pm US/Central	Projects to search WIMPS and neutrinoless double beta decays at the Center for Underground Physics			The Dark Energy Survey (DES) is an ongoing Stage III cosmology survey in optical to near-infrared wavelengths. I will briefly review the current state of the survey and demonstrate how ongoing improvements of data quality and consistency have enabled the first publication based on DES data, a lensing analysis of four massive galaxy clusters. I... More »
May 12, 2014, 2:00 pm US/Central	Searching for Axions			The axion is a hypothetical elementary particle whose existence would explain the baffling absence of CP violation in the strong interactions. Axions also happen to be a good dark-matter candidate. Even if dark-matter axions comprised the overwhelming majority of mass in the universe, they would be extraordinarily difficult to detect. However, several experiments are either... More »
June 2, 2014, 2:00 pm US/Central	Introducing Clustering Redshifts			I will present a new method to infer the redshift distribution of astronomical datasets. The technique, based on spatial correlations, can be applied to any photometric sample, discrete or continuous, and at any wavelength. I will present a number of results using datasets in the UV, optical, IR and radio wavelengths. Notes: 1304
June 9, 2014, 2:00 pm US/Central	SPIDER: A Balloon-Borne Polarimeter for Cosmic Microwave Background Observation			SPIDER is a balloon-borne polarimeter designed to characterize the primordial gravitational wave signal in the degree-scale B-mode polarization of the cosmic microwave background (CMB). With six independent telescopes housing a total of 2000 detectors in the 90 GHz and 150 GHz frequency bands, SPIDER is poised to be the most sensitive CMB polarimeter on the... More »
June 16, 2014, 2:00 pm US/Central	A WISE search for large extraterrestrial civilizations: a complementary approach to traditional SETI			If alien civilizations exist throughout the universe, many have had billions of years to develop technology, expand their population and energy supplies, and travel across their galaxies. Kardashev classified hypothetical advanced civilizations by the magnitude of their power supply, with Type II civilizations harnessing most of the energy output of their host star, and Type... More »
June 17, 2014, 2:00 pm US/Central	Digital Readout for UV through Near-IR MKIDs			ARCONS, the ARray Camera for Optical to Near-IR Spectrophotometry, is a photon counting integral field unit optimized to observe 400-1100 nm. It is built around a 2024 pixel array of MKIDs (Microwave Kinetic Inductance Detectors), an emerging superconducting detector technology. MKIDs are frequency domain multiplexed and are read out over two feedlines, using tones at... More »
June 23, 2014, 2:00 pm US/Central	Evidence for High Energy Astrophysical Muon Neutrinos with IceCube			One of the long-standing goals of high energy neutrino astronomy has been to observe muons produced by muon neutrinos which, due to their ability to point back along their direction of travel, can pave the way to locating astrophysical sources of neutrinos and cosmic rays. In this talk I will show preliminary results from a... More »
July 30, 2014, 10:30 am US/Central	The Growth of Supermassive Black Holes with their Co-Evolution with Galaxies			Using multi-wavelength surveys like GOODS, COSMOS, and Stripe 82X, we measure the growth of supermassive black holes at the centers of galaxies over the last 10 billion years. Most actively growing black holes are heavily obscured and thus are not seen in large area optical surveys like the Sloan Digital Sky Survey; furthermore, obscuration is... More »
Aug. 6, 2014, 2:30 pm US/Central	Understanding Cosmic Acceleration with DES and Beyond			The Dark Energy Survey (DES) is a large imaging sky survey designed to enable us to understand the physics underlying the accelerated expansion of the Universe. Cosmic acceleration can be explained either by invoking a new energy component to the Universe, dark energy, or by introducing a new fundamental theory of gravity. In either case... More »
Aug. 12, 2014, 11:00 am US/Central	Facing the challenge: Gravitational lensing in DES			The Dark Energy Survey (DES) is an ongoing Stage III cosmology survey in optical to near-infrared wavelengths. I will briefly review the current state of the survey and demonstrate how ongoing improvements of data quality and consistency have enabled the first publication based on DES data, a lensing analysis of four massive galaxy clusters. I... More »
Sept. 8, 2014, 11:00 am US/Central	Time Delay Cosmology			Thousands of strong gravitational lenses will be found by time domain surveys such as DES and LSST. Time delays between multiple images can be used to form a geometric time delay distance, a cosmological probe with some unique sensitivities and complementarities. In addition to the cosmology impact, I discuss the statistics challenge of accurate estimation... More »
Sept. 15, 2014, 2:00 pm US/Central	New Physics and Indirect Dark Matter Detection			Can we learn about New Physics with astronomical and astro-particle data? Understanding how this is possible is key to unraveling one of the most pressing mysteries at the interface of cosmology and particle physics: the fundamental nature of dark matter. I will discuss some of the recent puzzling findings in astro-particle and astronomical observations that... More »
Sept. 22, 2014, 2:00 pm US/Central	Testing Neutrino Properties with Large-scale Structure			The large-scale structure of our universe (the distribution of galaxies on very large-scales for instance) contains a wealth of information about the origin, evolution, and matter content of the universe. I will discuss physical effects of the cosmic neutrino background on the process of structure formation and present new signatures of massive cosmic background neutrinos... More »
Sept. 29, 2014, 2:00 pm US/Central	The Ice Cube Puzzle			Astrophysical neutrinos are unambiguous tracers of hadronic interactions of cosmic rays (CRs) in our Universe. With this in mind, high energy neutrino astronomy has long been anticipated to help uncover the origin of high energy CRs. The recent detection of a flux of high-energy extraterrestrial neutrinos by the IceCube Observatory is an important step in... More »
Oct. 6, 2014, 2:00 pm US/Central	Implications of the Candidate Dark Matter Decay Line at 3.5 keV			Two independent groups have detected an unidentified X-ray line at 3.5 keV that is consistent with the dark matter density in the field of view of the observations toward the Perseus Cluster, stacked X-ray clusters, Andromeda, and the Milky Way Galactic Center. I will discuss the sterile neutrino dark matter decay interpretation of the line,... More »
Oct. 13, 2014, 2:00 pm US/Central	Lyman alpha Forest in optically thin cosmological simulations			The Lyman-alpha forest is the main tracer of cosmological structure at high redshifts, 2<z<4, accessible to current (BOSS/eBOSS) and future (DESI) sky surveys. On large-scales, the Ly-a power spectrum is used as a standard ruler, measuring the Baryon acoustic oscillations (BAO) scale at high redshifts. On small-scales, the Ly-a forest allows one to constrain neutrino... More »
Oct. 20, 2014, 2:00 pm US/Central	Cosmic Reionization on Computers			I will review the field of numerical simulations of cosmic reionization: the process of ionizing of intergalactic medium by high redshift galaxies and quasars. I will describe the main physical processes that are important for modeling reionization, explain how these processes are incorporated in computer simulations, and will use simulations to gain insight into the... More »
Oct. 27, 2014, 2:00 pm US/Central	Cosmic ray anisotropies and nearby sources			Recently, the AMS-02 collaboration has presented data on cosmic ray protons, Helium, electrons and positrons as well as the boron-to-carbon ratio. We present the first consistent modeling of these data, paying particular attention to the contribution due to production and acceleration of secondary electrons and positrons in nearby supernova remnants. This process results in an... More »
Nov. 3, 2014, 2:00 pm US/Central	Cosmic Reionization			Cosmic reionization, and the preceding ‘dark ages’, corresponds to the epoch when light from the first galaxies reionized the neutral intergalactic medium (IGM) that pervaded the Universe following recombination. This epoch is the last frontier in the study of cosmic evolution, corresponding to the formation of the first galaxies and black holes. I will discuss... More »
Nov. 10, 2014, 2:00 pm US/Central	The non-universality of halo density profiles			The density profiles of dark matter halos are an essential input for models of galaxy formation, as well as for the interpretation of numerous observations such as weak and strong lensing signals. The profiles are commonly thought to follow a simple, universal shape, and only depend on two parameters, mass and concentration. Using a large... More »
Nov. 14, 2014, 10:00 am US/Central	The axion search plan at the Center for Axion and Precision Physics in Korea			The center for axion and precision physics research (CAPP) in Korea is recently been established by the Institute for Basic Science (IBS) of South Korea to establish a state of the art axion dark matter experiment in Korea and play a leadership role in the storage ring proton EDM experiment. With a number of new... More »
Nov. 17, 2014, 2:00 pm US/Central	Probing Dark Energy with the Canadian Hydrogen Intensity Mapping Experiment (CHIME)			CHIME will use the 21cm emission line of neutral hydrogen to map large-scale structure between redshifts of 0.8 and 2.5. By measuring BAO we will place constraints on the dark energy equation of state as it begins to dominate the expansion of the Universe, particularly at redshifts poorly probed by current BAO surveys. In this... More »
Nov. 20, 2014, 1:30 pm US/Central	Dark Matter Complementarity			The cosmic reionization, and the preceding ‘dark ages’, corresponds to the epoch when light from the first galaxies reionized the neutral intergalactic medium (IGM) that pervaded the Universe following recombination. This epoch is the last frontier in the study of cosmic evolution, corresponding to the formation of the first galaxies and black holes. I will... More »
Nov. 24, 2014, 2:00 pm US/Central	MKIDs at FNAL: From Detector R&D to Dark Energy Science			We will discuss the progress done over the last couple of years on R&D for UV-VIS-IR MKIDs. This will include a description of the activities in the lab, and at telescopes. We will also present our plans for a prototype instrument at the 4m telescope at SOAR. Finally, the potential of these sensors as new... More »
Dec. 8, 2014, 2:00 pm US/Central	Planck 2014 Cosmology Results			The Planck 2014 cosmology likelihood will include the tightest measurements to-date of CMB polarization at intermediate angular scales. I will present parameter constraints on LCDM and extensions from these data, including on the effective number and masses of the neutrinos, as well as other parameters describing dark matter, axions, and inflation. In doing so, I... More »
Dec. 15, 2014, 2:00 pm US/Central	The outskirts of Milky-Way mass galaxies - a probe of dark matter driven growth			Dark matter is central to our idea of how galaxies grow and develop. Dark matter overdensities trigger the initial collapse, dark matter halos merge and grow continuously to the present day, and dark matter constitutes most of the gravitationally important mass in present-day galaxies. Yet, we know precious little about the actual dark matter merger... More »
Dec. 16, 2014, 1:00 pm US/Central	Optical Spectroscopy with Starbugs, from TAIPAN to the Giant Magellan Telescope			The majority of astronomical fibre-fed spectroscopic instruments rely on sequential positioning of fibres that require significant time (up to an hour in some cases) to reconfigure a field for observation, thus reducing the amount of on-sky time available for any instrument. Starbugs, a novel fibre-positioning technology developed by the Australian Astronomical Observatory, allow for simultaneous... More »
Jan. 5, 2015, 2:00 pm US/Central	Measuring ultra-large cosmological scales with radio telescopes			Surveys of large-scale structure using the next generation of radio telescopes will be capable of probing unprecedentedly large volumes of the Universe. This will make it possible to detect effects that occur on length scales on the order of the cosmological horizon size, including primordial non-Gaussianity, general relativistic corrections, and possible signatures of modified gravity.... More »
Jan. 12, 2015, 2:00 pm US/Central	Formulation of the First Galaxies under Stellar Feedback			The first galaxies, which formed a few hundred million years after the big bang, are related to important cosmological questions. Given that they are thought to be the basic building blocks of large galaxies seen today, understanding their formation and properties is essential to studying galaxy formation as a whole. In this talk, I will... More »
Jan. 20, 2015, 2:00 pm US/Central	Towards precision cosmology: the halo model and necessary modifications			There are several approaches to account for clustering of matter and its evolution in the Universe. One of the more successful frameworks is the halo model. In this approach, all the matter in the Universe is assumed to be in isolated haloes with mass defined by a threshold density. Despite its success over a decade... More »
Feb. 2, 2015, 2:00 pm US/Central	Status of DAMIC at SNOLAB			I will present the recent progress achieved by the DAMIC Collaboration in the installation of charge-coupled devices (CCDs) as dark matter detectors in the low background environment of SNOLAB. I will give an overview of the CCD performance, in particular the continuous, low noise (7 eV RMS) operation of the devices under the conditions for... More »
Feb. 9, 2015, 2:00 pm US/Central	Baryon Acoustic Oscillations and Redshift Space Distortions			The talk will present results about measuring the Baryon Acoustic Oscillation signal in redshift surveys. The impacts of various effects like survey geometries, redshift space distortions, and nonlinear corrections will be discussed. In particular, we will show that redshift-space distortions can substantially sharpen the BAO peak in directions close to the line of sight. We... More »
Feb. 16, 2015, 2:00 pm US/Central	Building tomorrow's submm-wavelength instruments with kinetic inductance detectors and on-chip band-defining circuits			Recent advances in detector technology have enabled precision studies of the Cosmic Microwave Background and of the dusty high-redshift galaxies that played host to the first generations of star formation. However, there remain significant scientific questions which can only be addressed with massive 100-kilopixel scale cameras, wide-band multichroaic pixels, and compact multi-object spectrometers. I’ll discuss... More »
Feb. 23, 2015, 12:30 pm US/Central	Probing the Ultra-High Energy Universe with the Greenland Neutrino Observatory			Ultra-high energy neutrino astronomy sits at the boundary between particle physics and astrophysics. Through neutrino astrophysics, we can probe the nature of the ultra-high energy universe in a unique way and test our understanding of particle physics at energies much greater than those achievable at particle colliders. The best limit to date on the flux... More »
March 2, 2015, 2:00 pm US/Central	Modeling the Evolution of Galaxy Properties with the Illustris Simulation			Cosmological simulations are among the most powerful tools available to probe the non-linear regime of cosmic structure formation. They also provide one of the most powerful testbeds for understanding the impact that hydrodynamics and feedback processes have on the evolution of galaxies. In my talk, I will present galaxy formation simulations that couple a novel... More »
March 9, 2015, 2:00 pm US/Central	GRBs, LIGO, and multi-messenger astronomy			LIGO should be on the verge of directly detecting gravitational waves. The most likely sources are the inspirals and mergers of stellar mass binary systems, such as pairs of neutron stars and/or black holes. In addition to being extraordinarily loud in gravitational waves, these coalescences may be associated with short gamma-ray bursts, and thus hold... More »
March 10, 2015, 2:00 pm US/Central	Impacts of Galaxy Formation and Alternative Dark Matter Models on Milky Way Satellite Kinematics			We apply the Jeans equation to identify subhalos in high-resolution numerical simulations that are potentially consistent with observed properties of Milky Way dwarf spheroidal (dSph) galaxies. We investigate the effects found by several recent studies that show changes to the dynamical properties of galactic substructure: the properties of dark matter (DM), and galaxy formation physics.... More »
March 17, 2015, 2:00 pm US/Central	Baryon Acoustic Oscillations: A Robust and Precise Route to the Cosmological Distance Scale			I will discuss how the acoustic oscillations that propagate in the photon-baryon fluid during the first million years of the Universe provide a robust method for measuring the cosmological distance scale. The distance that the sound can travel can be computed to high precision and creates a signature in the late-time clustering of matter that... More »
March 23, 2015, 2:00 pm US/Central	Testing the accuracy of the Frontier-Fields Observatory of Bologna			I will show the preliminary results of the Frontier Fields Lens Modeling Comparison Project. The Frontier Field Initiative is currently a major effort of the HST to provide ultra-deep observations of up to six strong lensing clusters. The goal of this survey is to combine the sensitivity of HST with the magnification power of these... More »
March 30, 2015, 2:00 pm US/Central	The Milky Way's stellar and dark mass distributions			Observations of the structure and dynamics of different stellar populations in the Milky Way’s disk provide a unique perspective on disk formation, evolution, and dynamics. I will present recent progress in our knowledge of the chemo-orbital structure of the disk and discuss the implications for our understanding of how the Milky Way formed and evolved... More »
March 31, 2015, 2:00 pm US/Central	A search for dark matter annihilation in the newly discovered dwarf galaxy Reticulum 2			I will present results from a search for gamma-ray emission in nine Milky Way satellites recently discovered in the Dark Energy Survey. The nearest of these, Reticulum 2, shows evidence for a signal in public Fermi data. The detected emission is consistent with annihilating dark matter with a particle mass less than a few hundred... More »
April 6, 2015, 2:00 pm US/Central	Status of the DarkSide experiment			DarkSide-50 is a direct-detection dark matter experiment operating at the Gran Sasso National Laboratory, searching for nuclear recoils possibly induced by Weakly Interacting Massive Particles (WIMPs). The detector is a 50 kg liquid argon Time Projection Chamber (TPC) that is surrounded by an organic liquid scintillator neutron veto and a water Cherenkov cosmogenic veto. I... More »
April 20, 2015, 2:00 pm US/Central	Enabling Dark Energy Survey Science with redMaPPer and redMaGic			The Dark Energy Survey is currently taking data, and is poised to be the leading Dark Energy experiment of the second half of this decade. I will present the redMaPPer and redMaGic algorithms, designed to photometrically select clusters and luminous red galaxies respectively, discussing their performance, and how they will enable cluster abundance and baryon... More »
April 27, 2015, 2:00 pm US/Central	The Evolution of Quasars with Cosmic Time			While the luminosity and mass distributions of quasars has evolved dramatically with cosmic time, the physical properties of quasars of a given luminosity are remarkably independent of redshift. I will describe recent results on the spectra of luminous quasars, the dark matter halos in which they sit, and the intergalactic medium of their host galaxies,... More »
May 6, 2015, 2:00 pm US/Central	Probing New Physics Beyond the Standard Model with Cosmology			Cosmological observations have provided us with answers to age-old questions, involving the age, geometry, and composition of the universe. However, there are profound questions that still remain unanswered. In this talk, I will describe ongoing efforts to shed light on some of these questions. The origin of the small anisotropies that later grew into the... More »
May 18, 2015, 2:00 pm US/Central	Particle Physics at the Yoctowatt Scale: The ADMX-HF Experiment			The axion is a hypothetical particle first postulated to explain the absence of CP violation in strong interactions; it is also a well-motivated cold dark matter candidate. Dark matter axions may be detected via their resonant conversion into photons in a high-Q microwave cavity permeated by a strong magnetic field. The Axion Dark Matter eXperiment... More »
May 26, 2015, 2:00 pm US/Central	The vicissitudes of the cold dark matter model of cosmology			One of the most impressive advances in Physics and Astronomy over the past three decades is the development of the ”standard model of cosmology,” LCDM (where L stands for Einstein’s cosmological constant and CDM for cold dark matter). LCDM accounts for an impressive array of data on the structure of the Universe on large-scale scales,... More »
June 1, 2015, 2:00 pm US/Central	The Present and Future of Multi-Object Fiber Spectroscopy			The Michigan/Magellan Fiber System (M2FS) has been operational for almost two years and has carried out a wide range of studies from searching for exoplanets, to probing the dark matter content of nearby galaxies, to mapping the distribution of high-redshift galaxies at redshifts of 4-6. I describe some of these results and also discuss how... More »
June 8, 2015, 2:00 pm US/Central	SPIDER: exploring the dawn of time from above the clouds			TEST Our account of cosmic history begins with inflation, a moment of rapid expansion that set the stage for our universe’s evolution. This inflationary epoch should have left a very faint imprint upon the sky at millimeter wavelengths: a “B-mode” (odd-parity) pattern of polarization in the cosmic microwave background (CMB). January 1st saw the successful... More »
Nov. 9, 2015, 2:00 pm US/Central	The Nearby Universe as a Cosmological Lens			Over the last decade, large sky surveys have revolutionized our view of the Milky Way and the dwarf galaxies orbiting around it. Much of this observational progress has been motivated by a series of apparent “crises” for the cold dark matter cosmological model. However, these challenges have effectively functioned as flashlights pointing us to interesting... More »
Nov. 16, 2015, 2:00 pm US/Central	The Future of Large Mass Calorimeters			The detector technology behind SuperCDMS is nearly 20 years old, and thus there is quite reasonable assumption in the scientific community that it is has reached maturity. Alas, this isn’t the case at all! In this talk, I’ll discuss how we hope to improve the energy sensitivity of athermal phonon detectors by 2 orders of... More »
Nov. 23, 2015, 2:00 pm US/Central	Darkside-50: Results with UAr			DarkSide-50 (DS-50) at Gran Sasso underground laboratory, Italy, is a direct dark matter search experiment based on a Time Projection Chamber (TPC) with liquid argon from underground sources. The DS-50 TPC, with 50 kg of active argon and a fiducial mass of ~37 kg, is installed inside an active neutron veto based on a boron-loaded... More »
Nov. 30, 2015, 2:00 pm US/Central	Antimatter Gravity with Muons			A longstanding question in physics is whether antimatter falls up. If it does, a simpler cosmology, with no inflation or baryon asymmetry, and no need for dark matter and energy, may be possible. Alternatively, antimatter may fall at nearly the same rate as matter, but violate the equivalence principle slightly, pointing towards a future quantum... More »
Dec. 7, 2015, 2:00 pm US/Central	PICO bubble chambers for dark matter			The PICO Collaboration, formed from the merger of the Chicago-based COUPP and the Canadian-based PICASSO experiments, uses bubble chambers to search for dark matter. Bubble chambers are a unique dark matter detector technology. They provide very high 10^10 intrinsic electron recoil rejection, the ability to switch nuclear targets, acoustic rejection of alpha events, simple data... More »
Dec. 14, 2015, 2:00 am US/Central	Recent Results and Future Prospects in UHECR Observations			Ultra-high energy cosmic rays (UHECRs) are the most energetic particles in the universe. Their origins could be related to extremely energetic astronomical phenomena or other exotic processes, such as the decay of the super-heavy dark matter in the halo of our galaxy or topological defects created in an early phase of the development of the... More »
Jan. 11, 2016, 2:00 am US/Central	Fast Radio Bursts			I will report on the discovery of a new fast radio burst with a detection of Faraday rotation, wavelength-dependent scattering, and scintillation. The data imply source location in the dense central region of its host galaxy or the presence of magnetized material associated with the source itself. The burst was detected with GBT at 800MHz.... More »
Jan. 25, 2016, 2:00 am US/Central	Advances in millimeter-wavelength instrumentation with the South Pole Telescope			The Cosmic Microwave Background (CMB) is a powerful cosmological tool, containing the imprint of signals from both the early and late universe. Over the past few years, CMB experiments made significant technological advances that led to the first detection of the extremely faint B-mode polarization signal. Using this signal, experiments have the potential to constrain... More »
Feb. 1, 2016, 2:00 pm US/Central	Quantum Twists of Space			The talk will review theoretical arguments that if space and time emerge from a quantum system at the Planck scale, there should be nonlocal exotic quantum correlations of positions of massive bodies, even on scales much larger than the Planck length. In relational theories with no fixed background space, these could take the form of... More »
Feb. 8, 2016, 2:00 pm US/Central	Helical Magnetic Fields in the Cosmos			It is often necessary to study cosmological phase transitions, such as inflation and thermal symmetry-breaking phenomena, through the relics that they leave behind. In this sense, the cosmological magnetic field may be a powerful probe of the early universe, which has yet to be tapped. In this talk, I will survey various topics related to... More »
Feb. 15, 2016, 2:00 pm US/Central	CRESST: A direct search for (light) dark matter particles			Today, many observations on various astronomical scales provide compelling evidence for the existence of dark matter. Its underlying nature, however, remains an open question of present-day physics. Direct searches aim to find the answer by observing dark matter particles interacting in their detectors. One of the numerous experiments around the globe is CRESST-II, the only... More »
Feb. 22, 2016, 2:00 pm US/Central	Pulsar timing limit on gravitational waves necessitates re-assessment of binary supermassive black hole population			Mergers of massive galaxies are thought to form binary supermassive black holes, which coalesce through losses of energy and angular momentum to gravitational radiation. For the last decade, collaborations worldwide have been searching for signatures of these gravitational waves in radio timing measurements of millisecond pulsars. The intended sensitivities of these experiments, based on theoretical predictions,... More »
Feb. 29, 2016, 2:00 pm US/Central	Chameleon dark energy			If dark energy consists of a light scalar field, it might be detectable as a “fifth force” between ordinary-matter objects, in potential conflict with precision tests of gravity. Chameleon fields and other theories with screening mechanisms, however, can evade these tests by suppressing the forces in regions of high density, such as the laboratory. The... More »
March 7, 2016, 2:00 pm US/Central	New Cosmological Results from Type Ia Supernovae			Type Ia Supernovae play a critical role in measuring dark energy as well as the Hubble Constant. I will go over the latest results from each of these important measurements. I will also discuss the latest interpretations about possible `tension’ in these measurements from different probes including BAO and CMB. I will show what role... More »
March 14, 2016, 2:00 pm US/Central	Always in the Last Place You Look: Three New Directions for Dark Matter Detection			Searches for dark matter over the last two decades have mainly focused on the Weak-scale mass range. With no detection yet, either in underground searches or the LHC, our best hope going forward is to expand our search to cover as many types of dark matter as possible. I will discuss three budding direct detection... More »
March 21, 2016, 2:00 pm US/Central	Next Generation Cosmological Constraints on the Dark Sector and Gravity			A rich portfolio of upcoming complementary cosmological experiments will be producing data in the next 5-10 years. I will discuss the goals of the LSST Dark Energy Science Collaboration and the challenges faced to achieve them. I will also discuss ways in which LSST and the other surveys can be used in conjunction to extract... More »
March 28, 2016, 2:00 pm US/Central	TBA
March 28, 2016, 2:00 pm US/Central	Joining Forces against the Dark Side of the Universe: From the Cosmic Microwave Background to the Large Scale Structure			Despite tremendous recent progress, gaps remain in our knowledge of our understanding of the Universe. We have not yet pinned down the properties of dark energy, nor have we confirmed Einstein’s theory of Gravity at the largest scales. Current and upcoming large sky surveys of the Cosmic Microwave Background (CMB), Large Scale Structure (LSS) in... More »
April 4, 2016, 2:00 pm US/Central	From Detector to Observatory			On September 14, 2015 LIGO made the first direct detection of gravitational waves, marking the transition of the LIGO instruments from detectors to observatories, and the beginning of the era of gravitational wave astronomy. GW150914 provided the first observational proof that binary black holes not only exist, but that they exist in large numbers and... More »
April 11, 2016, 2:00 pm US/Central	Special Colloquium (Title TBD)			TBD
April 18, 2016, 2:00 pm US/Central	Baryogenesis via Particle-Antiparticle Oscillations			CP violation, which is crucial for producing the baryon asymmetry of the Universe, is enhanced in particle-antiparticle oscillations. We study particle-antiparticle oscillations (of a particle with mass O(100 GeV)) with CP violation in the early Universe in the presence of interactions with O(ab-fb) cross-sections. We show that, if baryon-number-violating interactions exist, a baryon asymmetry can... More »
April 25, 2016, 2:00 pm US/Central	Stellar-Dynamical Inferences about Dark Matter in the Smallest Galaxies			The Local Group’s dwarf galaxies include the nearest, smallest, oldest, darkest and least chemically-enriched galaxies known. I will summarize recent results – and present new ones – regarding the amount and spatial distribution of dark matter within these systems. Implications range from tests of the standard `cold dark matter’ model of cosmological structure formation to... More »
May 2, 2016, 2:00 pm US/Central	Cosmological Seed Magnetic Field from Inflation			A cosmological magnetic field of nG strength on Mpc length scales could be the seed magnetic field needed to explain observed few microG large-scale galactic magnetic fields. I first briefly review the observational and theoretical motivations for such a seed field, two galactic magnetic field amplification models, and some non-inflationary seed field generation scenarios. I... More »
May 11, 2016, 2:00 pm US/Central	Resolving the Isotropic Gamma-Ray Background in the Search for Dark Matter			The presence of all-sky, diffuse gamma-ray emission has been known for several decades, but its origins remain an open question. While astrophysical sources such as Active Galactic Nuclei and star-forming galaxies almost certainly contribute to this Isotropic Gamma-Ray Background (IGRB), dark-matter annihilation may also leave an imprint. Therefore, resolving the components of the IGRB is... More »
May 11, 2016, 2:00 pm US/Central	Resolving the Isotropic Gamma-Ray Background in the Search for Dark Matter			The presence of all-sky, diffuse gamma-ray emission has been known for several decades, but its origins remain an open question. While astrophysical sources such as Active Galactic Nuclei and star-forming galaxies almost certainly contribute to this Isotropic Gamma-Ray Background (IGRB), dark-matter annihilation may also leave an imprint. Therefore, resolving the components of the IGRB is... More »
May 16, 2016, 2:00 pm US/Central	Searching for Dark Matter with Sounding Rockets			High-resolution X-ray spectrometers onboard suborbital sounding rockets can search for dark matter candidates that produce X-ray lines, such as decaying keV-scale sterile neutrinos. Even with exposure times and effective areas far smaller than XMM and Chandra observations, high-resolution, wide field-of-view observations with sounding rockets have competitive sensitivity to decaying sterile neutrinos. We analyze a subset... More »
May 23, 2016, 2:00 pm US/Central	Simulations of Strong Gravitational Lensing			Gravitational lensing is one of the most powerful tools for investigating the dark side of the Universe. Strong gravitational lensing in particular provides a unique probe of the cores of massive dark matter halos. However, understanding this phenomena based upon observational data alone is complicated; high-fidelity simulations are required for robust cosmological interpretations. To fulfill... More »
May 23, 2016, 2:00 pm US/Central	Simulations of Strong Gravitational Lensing			Gravitational lensing is one of the most powerful tools for investigating the dark side of the Universe. Strong gravitational lensing in particular provides a unique probe of the cores of massive dark matter halos. However, understanding this phenomena based upon observational data alone is complicated; high-fidelity simulations are required for robust cosmological interpretations. To fulfill... More »
June 6, 2016, 2:00 pm US/Central	Galaxy Cluster Cosmology with the South Pole Telescope			Measurements of the abundance of galaxy clusters are an established cosmological probe and a promising tool for measuring the properties of dark energy and cosmic structure formation. To achieve the required level of accuracy, a clean survey selection and robust mass calibration from various observables is crucial. In this talk, I will review the cluster... More »
June 27, 2016, 2:00 pm US/Central	Interpreting Observations of Galaxy Cluster Outskirts			A variety of astrophysical processes affect the evolution of the intracluster medium (ICM) and corresponding observational signatures. While gas in the cluster core is most sensitive to cooling and feedback processes, gas in cluster outskirts is most sensitive to physical processes driven by accretion. I will present cosmological simulations of galaxy cluster formation that follow... More »
July 18, 2016, 2:00 pm US/Central	Observations and Simulations of Galaxy Clusters: Cluster Radio Galaxies and their Implications on SZE Signal, Simulated Pressure Profiles and SZE Mass-Observable Relation			We study the overdensity of point sources in the direction of X-ray-selected galaxy clusters from the Meta-Catalog of X-ray detected Clusters of galaxies (MCXC; ⟨z⟩ = 0.14) at South Pole Telescope (SPT) and Sydney University Molonglo Sky Survey (SUMSS) frequencies. Flux densities at 95, 150 and 220 GHz are extracted from the 2500 deg2 SPT-SZ... More »
Aug. 15, 2016, 2:00 pm US/Central	The multiple effects of AGN feedback in galaxy clusters			TBA
Sept. 12, 2016, 2:00 pm US/Central	Scintillating bubble chambers: Results from a 35-gram prototype xenon bubble chamber			In both direct WIMP dark matter search and coherent neutrino-nucleus elastic scattering experiments, discriminating low-energy nuclear recoils from all the other backgrounds is the key to detector performance. The bubble chambers developed by the PICO collaboration for dark matter detection feature both unmatched electron-recoil background rejection and the unique ability to work with a variety... More »
Sept. 19, 2016, 2:00 pm US/Central	Neutrino Decay and Non-Unitary Effects in Neutrino Oscillations			Discussion on current bounds on the neutrino lifetime, along with a more general parameterization of “general decay” effects in neutrino flavor oscillation.
Sept. 26, 2016, 2:00 pm US/Central	Early Reionization Science from 21cm Experiments and the Path Towards a New Cosmological Probe			21 cm cosmology — the concept of using radio telescopes to observe the highly redshifted 21 cm line of neutral hydrogen on cosmological scales — is a field on the verge of a breakthrough. The first generation of 21 cm cosmology experiments (LOFAR, MWA, and PAPER, among others) have been operating for several years,... More »
Sept. 26, 2016, 2:00 pm US/Central	Early Reionization Science from 21cm Experiments and the Path Towards a New Cosmological Probe			21 cm cosmology — the concept of using radio telescopes to observe the highly redshifted 21 cm line of neutral hydrogen on cosmological scales — is a field on the verge of a breakthrough. The first generation of 21 cm cosmology experiments (LOFAR, MWA, and PAPER, among others) have been operating for several years, and... More »
Oct. 10, 2016, 2:00 pm US/Central	Searches for New Physics with X-ray data			A discussion on searches for new physics using ultra-deep X-ray observations of the central Active Galactic Nucleus of the Perseus galaxy cluster. We find two anomalies at high significance that we are unable to account for through conventional instrumental or astrophysical processes. I will outline interpretations of these anomalies from axion-photon mixing and from a... More »
Oct. 17, 2016, 2:00 pm US/Central	Soft Limits, Asymptotic Symmetries and Inflation in Flatland			There has been much recent interest in soft limits, both of flat space S-Matrix elements and of cosmological correlation functions. We will discuss the physics probed by soft limits in cosmology and explore the connection between cosmological soft theorems and asymptotic symmetries. These ideas will be illustrated by a simple example: inflation in 2+1 dimensions.
Oct. 31, 2016, 2:00 pm US/Central	Recent Results from the PandaX- II experiments			The Particle and Astrophysical Xenon (PandaX) project is a series of xenon-based ultra-low background experiments in the China JinPing Underground Laboratory (CJPL) targeting the unknown physics of dark matter and neutrinos. The first and second stage experiments (PandaX-I and II) both utilize dual-phase xenon time projection chamber (TPC) to carry out direct search for the... More »
Nov. 7, 2016, 2:00 pm US/Central	Baryon Component Covariance and Stacked Spectroscopic Masses of Galaxy Clusters			This talk will cover recent improvements to the characterization of the cosmic population of massive halos. After briefly reviewing an underlying statistical model for multi-property counts and conditional statistics, I will present preliminary observational confirmation of the “closed box” baryonic nature of massive halos predicted by simulations, then follow up with total mass scaling relations... More »
Nov. 14, 2016, 2:00 pm US/Central	Recent Results from APTpol:CMB Polarization on Small (and Large) Scales			The temperature and polarization of the cosmic microwave background (CMB) have been measured in exquisite detail by space-based probes such as WMAP and Planck over the full sky on large and intermediate scales. However, a healthy community of ground-based and balloon-borne experiments continue probing the CMB at both large and small scales with ever higher... More »
Nov. 21, 2016, 2:00 pm US/Central	Accelerating the Search for Dark Matter Axions with Quantum Technology			The axion is a hypothetical dark matter particle and many searches rely on its presumed coupling to electromagnetism. Indeed, these experiments amount to looking for an excess of microwave photons in a cryogenic microwave cavity. If all sources of technical noise can be tamed, the sensitivity is ultimately limited by fundamental quantum fluctuations of the... More »
Nov. 28, 2016, 2:00 pm US/Central	Search for Dark Matter in Terms of Dark Bound States			Understanding the nature of dark matter is an open question of central importance to particle physics and cosmology. In this talk, I discuss a model where the dark matter is a fermion charged under a dark U(1) gauge symmetry and its interactions are mediated by a massive dark photon. I will summarize the current status... More »
Dec. 5, 2016, 2:00 pm US/Central	A Monodromy from London			A description of large field inflation in terms of a dual massive gauge theory
Dec. 12, 2016, 2:00 pm US/Central	New Directions in Dark Matter Detection			Observational bounds currently permit the existence of a large number of dark matter candidates, ranging from ultra-light axions with masses ~ 10^(-22) eV to MACHOs with mass as large as 10^(24) gm. It is important to develop experimental methods to constrain this vast range of parameters. In this talk, I will describe new experimental methods... More »
Jan. 23, 2017, 2:00 pm US/Central	Coherent Neutrino-Nucleus Scattering: signal of background?			The next generation of dark matter direct detection experiments will be sensitive to coherent nuclear scattering of solar neutrinos. This presents an irreducible background to dark matter searches, the so called ‘neutrino floor’. However, this effect that has yet to be observed and so provides an opportunity for discovery. Dedicated experiments are racing to observe... More »
Jan. 30, 2017, 2:00 pm US/Central	The ANDES Deep Underground Laboratory in South America: status and prospects			The construction of the Agua Negra tunnel through the Andes between Argentina and Chile is a unique opportunity to build a world class deep underground laboratory in the southern hemisphere, with 1750m of rock overburden. At 30 degrees latitude south, far from nuclear power plants, it provides a unique site for Dark Matter searches and... More »
Feb. 6, 2017, 2:00 pm US/Central	Discovery of the First Quad(-like) Lensed Quasar System in the Dark Energy Survey			Strong gravitational lensing systems provide valuable tools for studying the properties and evolution of galaxies and quasars, for measuring the distribution of dark matter, and for constraining cosmological parameters. In particular, lensed quasar systems, when accompanied by accurate time delay measurements and careful lens modeling, can provide powerful cosmological constraints that are complementary to those... More »
Feb. 13, 2017, 2:00 pm US/Central	Canceled
Feb. 20, 2017, 2:00 pm US/Central	Cross-Correlating 2D and 3D Galaxy Surveys			Galaxy surveys probe both structure formation and the expansion rate, making them promising avenues for understanding the dark universe. Photometric surveys accurately map the 2D distribution of galaxy positions and shapes in a given redshift range, while spectroscopic surveys provide sparser 3D maps of the galaxy distribution. In this talk, I will present a way... More »
Feb. 27, 2017, 2:00 pm US/Central	Interplay between dark and baryonic matter in galaxy centers: new constraints from dynamics and lensing			The central 5-10 kpc of elliptical galaxies, while in long term steady state, are not truly relaxed. The primary reason is that baryons and dark matter are not fully mixed with each other. We demonstrate this by comparing observed and simulated galaxies to theoretically derived prediction for dynamically relaxed collisionless systems, and by examining the... More »
March 6, 2017, 2:00 pm US/Central	Direct Detection of sub-GeV Dark Matter			Dark matter with MeV-to-GeV masses is a theoretically and phenomenologically appealing possibility. In this talk, I will describe how direct-detection experiments can probe this under-explored mass range. A demonstrated technique with significant potential for improvement is that dark matter scatters off electrons, causing ionization or excitation of atoms in a detector target material, which can... More »
March 13, 2017, 2:00 pm US/Central	Cores in Dwarf Galaxies from Fermi Repulsion	James Unwin, UIC		Cold dark matter provides a remarkably good description of cosmology and astrophysics. However, observations connected with small scales might be in tension with this framework. In particular, structure formation simulations suggest that the density profiles of dwarf spheroidal galaxies should exhibit cusps, in contrast to observations. I will show that Fermi repulsion can explain the... More »
March 20, 2017, 2:00 pm US/Central	Compact dark matter	Marc Kamionkowski, Johns Hopkins		Considerable attention has focused the past year on the possibility that some or all of the dark matter could be composed of compact dark objects with masses around 30 solar masses. The hypothesis has led to interesting connections to gravitational-wave astrophysics, fast radio bursts, pulsar timing arrays, galaxy surveys, gravitational lensing, and stellar dynamics. I... More »
March 27, 2017, 2:00 pm US/Central	Weyl Symmetry, Inflation, and Spontaneous Generation of the Planck Mass	Christopher Hill, Fermilab		Scalar fields can be coupled non-minimally to curvature and satisfy: (i) the theory has no mass input parameters, including M_Planck=0; (ii) the scalars have arbitrary values and gradients, but undergo a general expansion and relaxation to constant values that satisfy a nontrivial elliptical constraint K(phi)=constant; (iii) this constraint breaks scale symmetry spontaneously, and the Planck... More »
April 3, 2017, 2:00 pm US/Central	New Insights into the Cosmic-Ray Positron Excess	Dan Hooper, Fermilab		Recent Measurements of the Gaming and B0656+14 pulsars by the gamma-ray telescope HAWC (along with earlier measurements by Milagro) indicate that these objects generate significant fluxes of very high-energy electrons. From the measured gamma-ray intensity and spectrum of these pulsars, one can calculate and constrain their expected contributions to the local cosmic-ray positron spectrum. Among... More »
April 10, 2017, 2:00 pm US/Central	Extrasolar Planets: Lessons From Kelper	Yoram Lithwick, Northwestern University		Astronomers have been discovering extrasolar planets at an astonishing pace. The Kepler space telescope has discovered thousands of planets smaller than Neptune. Many of these planets’ properties were completely unexpected, based on how planets were thought to form. I will describe these surprising properties, and explain how we have inferred the densities and eccentricities of... More »
April 17, 2017, 2:00 pm US/Central	The Search for Dark Photons at the SeaQuest E906 Experiment	Arun Tadepalli, Rutgers		The SeaQuest E906 experiment is a fixed target Drell-Yan experiment which is aimed at studying the anti-quark distributions in the nucleon and nuclei. 120 GeV protons from the Main Injector at Fermilab could also be used to search for massive dark gauge bosons or dark photons that could be generated when a proton beam dump... More »
April 24, 2017, 2:00 pm US/Central	Gamma-ray Constraints on Decaying Dark Matter and Implications for IceCube	Nicholas Rodd, MIT		Utilizing the Fermi measurement of the gamma-ray spectrum toward the inner Galaxy, I will explain how to derive some of the strongest constraints on dark matter lifetimes in the mass range from hundreds of MeV to above an EeV. The limits derived disfavour a decaying DM interpretation of the astrophysical neutrino flux observed by IceCube,... More »
May 1, 2017, 2:00 pm US/Central	Gravitational Lensing of the CMB	Gil Holder, UIUC		Gravitational lensing of the cosmic microwave background is emerging as a new and powerful cosmological tool. I will discuss recent results from the South Pole Telescope, as well as prospects for cosmological measurements of neutrino masses and detection of gravitational waves from the early universe.
May 8, 2017, 2:00 pm US/Central	A Cosmic Census – and the means to do it right	Peter Melchior, Princeton		Weak gravitational lensing is an important driver of large astronomical surveys. It presents the only way to determine the mass distribution in the universe over a wide range of scales: galaxies, galaxy clusters, voids, and the cosmic web as a whole. I will show the latest results of the Dark Energy Survey for each of... More »
May 15, 2017, 2:00 pm US/Central	Particle cosmological exploration for light dark matter	Kenji Kadota, Institute for Basic Science, S. Korea		A few examples for the light dark matter will be presented along with their cosmological (e.g. galaxies, supernova) and  the particle physics (collider, dark matter search) constraints to illustrate the complementarity between the particle physics and cosmology probes.
May 22, 2017, 2:00 pm US/Central	New Physics in Astrophysical Neutrino Flavor	Teppei Katori, Queen Mary		Neutrino oscillation physics is very successful in the last 20 years. Now, our understanding of the Neutrino Standard Model (nuSM) is very matured, and there are world wide effort to measure last missing pieces of nuSM. On the other hand, neutrino oscillation itself can be a tool to look for new physics beyond the nuSM,... More »
May 30, 2017, 2:00 pm US/Central	Twinkling Quasars Lensed by Galaxies Lensing Quasars	Paul Schechter, MIT		Nobody who has looked carefully at the two broad classes of stellar mass estimates for galaxies will question the need for another method. Quasars that are multiply imaged by galaxies twinkle as a result of micro-lensing by the stars that comprise the galaxies. We have used this to estimate stellar masses for the lensing galaxies. ... More »
June 5, 2017, 2:00 pm US/Central	Looking for the WIMP next door	Jessie Shelton, UIUC		Dark matter (DM) freezing out in a hidden sector is a simple and compelling scenario for the missing 25% of our universe, which can parametrically explain null results in searches to date. I will demonstrate that the requirement that the dark sector was once in thermal equilibrium with the SM defines a UV-insensitive cosmological history... More »
June 12, 2017, 2:00 pm US/Central	Lines, Excesses, and Dwarfs, Oh My! Dark Matter Searches and the Fermi-LAT sky	Regina Caputo, University of Maryland/NASA/GAFC		The era of precision cosmology has revealed that ~80% of the total amount of matter in the universe is dark matter. One promising candidate, motivated by both particle physics and astrophysics, is the Weakly Interacting Massive Particle (WIMP). WIMPs are predicted to produce gamma rays via annihilation or decay which are detectable by the Fermi... More »
June 19, 2017, 2:00 pm US/Central	LUX Postscripts and an LZ Preface	Kim Palladino, UW-Madison		Liquid xenon time projection chambers are a technology well suited to WIMP direct dark matter searches. The LUX detector completed operations in 2016, and has set its final spin-independent and spin-dependent limits, as well as a limit on axion-like particles. A second generation experiment, LZ, will occupy the cavern vacated by LUX. But first, we... More »
June 26, 2017, 2:00 pm US/Central	A New Look at Dark Matter in the Cores of galaxies	Thomas Lacroix, University of Montpellier / CNRS		Indirect detection techniques are a very promising avenue to look for dark matter (DM) particles by exploiting astrophysical observations. This is especially interesting when studying the centers of galaxies, where DM over-densities are expected. Moreover, DM particles may be significantly clustered in galactic cores around supermassive black holes, forming density spikes. I will present several... More »
July 5, 2017, 2:00 pm US/Central	Squeezed Light for Gravitational Wave Interferometers	Lee McCuller, MIT	Craig Hogan	Gravitational Wave detectors use optical interferometry enhanced with long baseline resonant cavities to achieve the sensitivity required for the recent detections of binary black hole inspirals. Advanced LIGO will soon add squeezed coherent states to enhance sensitivity by quantum mechanics. This talk will detail the detector and why this improvement will initially only improve the... More »
July 10, 2017, 2:00 pm US/Central	TBD	Annika Peter, Ohio State University
July 17, 2017, 2:00 pm US/Central	TBD	Mathias Pierre
July 24, 2017, 2:00 pm US/Central	AGN Feedback in Massive Galaxies	Pawel Biernacki, ETH-Zurich		Abstract: Supermassive Black Holes (SMBH) are found in the central region of massive galaxies at all redshift in the form of Active Galactic Nuclei (AGN) and are believed to regulate star formation in massive galaxies. Using improved sink particle algorithm to model SMBH in the RAMSES code we studied effects of coevolution of SMBH and... More »
July 31, 2017, 2:00 pm US/Central	No seminar -- DPF meeting
Aug. 7, 2017, 2:00 pm US/Central	Galaxy Clusters: A Standard Cannon for Cosmology	Chris Miller, University of Michigan		Einstein’s theory of general relativity (GR) entwines the dynamics of matter-energy and the universe’s expansion. It is often said: matter-energy tells space-time how to curve and space-time tells matter-energy how to move. In the weak-field limits of GR, Newtonian dynamics allows us to relate the escape speed to the local potential via the Poisson equation.... More »
Aug. 14, 2017, 2:00 pm US/Central	What We Can Tell About the Sources of IceCube’s Neutrinos, and What IceCube Can Tell Us About Gamma Ray Bursts	Peter Denton, Niels Bohr International Academy		IceCube has recently detected high energy astrophysical neutrinos for the first time. While many known astrophysical processes are anticipated to create high energy neutrinos, the origin of the observed neutrinos remains unclear. In this talk I will first present evidence disfavoring the Milky Way as the primary origin of the flux based on anisotropy arguments.... More »
Aug. 21, 2017, 2:00 pm US/Central	No seminar -- Solar Eclipse
Aug. 28, 2017, 2:00 pm US/Central	Cosmology with Clusters of Galaxies	Adam Mantz, Stanford		The gas mass fractions and the distribution in mass and redshift of the galaxy cluster population provide powerful probes of cosmology, constraining the cosmic matter density, the amplitude of the matter power spectrum, properties of dark energy, and the mass of neutrinos, among other parameters. Improvements in cluster data on several fronts have yielded significant... More »
Sept. 4, 2017, 2:00 pm US/Central	No seminar -- Labor Day
Sept. 11, 2017, 2:00 pm US/Central	Resolving the physical scale of star formation in a lensed galaxy at z=2.5	Traci Johnson, University of Michigan		Clumpy substructure in galaxies 1<z<3 is prevalent and forms from gravitational instabilities in the disk as cold gas accretes from the intergalactic medium. These clumps are the launching points of outflows from massive stars, and will merge over time to build up the exponential disks of today’s galaxies. Even with HST, the highest spatial resolution... More »
Sept. 18, 2017, 2:00 pm US/Central	TBD	Marilena Loverde, Stony Brook
Sept. 25, 2017, 2:00 pm US/Central	TBD	Vadim Semenov, University of Chicago
Oct. 2, 2017, 2:00 pm US/Central	TBD	Phil Cowperthwaite, Harvard
Oct. 9, 2017, 2:00 pm US/Central	TBD	Scott Hertel, University of Massachusetts Amherst
Oct. 16, 2017, 2:00 pm US/Central	TBD	Nick Battaglia, Princeton
Oct. 23, 2017, 2:30 pm US/Central	TBD	TBD
Oct. 30, 2017, 2:00 pm US/Central	TBD	TBD
Nov. 6, 2017, 2:00 pm US/Central	TBD	Liang Dai, Princeton
Nov. 13, 2017, 2:00 pm US/Central	TBD	Peter Behroozi, University of Arizona
Nov. 20, 2017, 2:00 pm US/Central	TBD	Robert Lasenby, Perimeter
Nov. 27, 2017, 2:00 pm US/Central	TBD	TBD
Dec. 4, 2017, 2:00 pm US/Central	TBD	TBD
Dec. 11, 2017, 2:00 pm US/Central	TBD	Doug Finkbeiner, Harvard
Dec. 18, 2017, 2:00 pm US/Central	TBD	TBD
Feb. 26, 2018, 2:00 pm US/Central	Stellar Streams Discovered in the Dark Energy Survey	Nora Shipp, U. Chicago	Yuanyuan Zhang	We perform a search for stellar streams around the Milky Way using the first three years of multi-band optical imaging data from the Dark Energy Survey (DES). We use DES data covering ∼5000 sq. deg. to a depth of g>23.5 with a relative photometric calibration uncertainty of <1%. This data set yields unprecedented sensitivity to... More »
Feb. 26, 2018, 2:00 pm US/Central	Stellar Streams Discovered in the Dark Energy Survey	Nora Shipp, U. Chicago		We perform a search for stellar streams around the Milky Way using the first three years of multi-band optical imaging data from the Dark Energy Survey (DES). We use DES data covering ∼5000 sq. deg. to a depth of g>23.5 with a relative photometric calibration uncertainty of <1%. This data set yields unprecedented sensitivity to... More »
March 5, 2018, 2:00 pm US/Central	TBD	Kimberly Boddy, Johns Hopkins
March 19, 2018, 2:00 pm US/Central	Intensity Interferometry in the Era of Giant Telescopes	Albert Stebbins, FNAL		Three widely separated 30m class optical telescopes (E-ELT, GMT, TMT) will start observations in the coming decade and will provide a new opportunity to probe moderately dim sources with unprecedented angular resolution using the spectroscopic count intensity interferometry technique (see Hanbury Brown and Twiss). The large baselines which extend up to 10,000 km probe angular... More »
March 26, 2018, 2:00 pm US/Central	TBD	Michael Cooper, UC Irvine
April 2, 2018, 2:00 pm US/Central	TBD	Mike Boylan-Kolchin, UT Austin
April 9, 2018, 2:00 pm US/Central	TBD	Andrew Long, U. Chicago KICP
April 16, 2018 US/Central	No Seminar (APS Meeting)	N/A
April 23, 2018, 2:00 pm US/Central	TBD	Mark Devlin, UPenn
April 30, 2018, 2:00 pm US/Central	TBD	Heidi Wu
May 7, 2018, 2:00 pm US/Central	TBD	Jason Detwiler, U Wisconsin Madison
May 21, 2018, 2:00 pm US/Central	TBD	Brian Keating, UC San Diego
May 30, 2018, 2:00 pm US/Central	Galaxy cluster mass measurements in the Dark Energy Survey	Tom McClintock, University of Arizona		Galaxy clusters are a powerful probe of cosmological parameters and host up to hundreds of galaxies. These clusters reside in massive dark matter halos, which are virialized structures comprised of up to a few times 10^15 solar masses. Forming the foundation of galaxy cluster cosmology are two critical components: measurements of cluster masses, and models... More »
June 4, 2018, 2:00 pm US/Central	Anisotropies in the Gravitational Wave Background from Cosmological Phase Transitions	Yuhsin Tsai, U Maryland		Phase transitions in the early universe can readily create an observable stochastic gravitational wave background. I will argue that such a background necessarily contains anisotropies analogous to those of the cosmic microwave background (CMB) of photons, and that these too may be within reach of proposed gravitational wave detectors. Correlations within the gravitational wave anisotropies... More »
June 11, 2018, 2:00 pm US/Central	The Linear Point: a cleaner cosmological standard ruler in the galaxy correlation	Stefano Anselmi, Observatoire de Paris		Cosmology has made fundamental progress thanks to the role of standard rulers: objects of known size that are constant in redshift. The acoustic peak in the large scale structure clustering correlation function is one of them. However, in the era of precision cosmology, its power has been highly challenged by late time non-linear effects that... More »
June 18, 2018, 2:00 pm US/Central	TBD	Oren Slone, Princeton
June 25, 2018, 2:00 pm US/Central	TBD	Julio Navarro, U Victoria
July 9, 2018, 2:00 pm US/Central	A New Frontier in the Search for Dark Matter	Gordan Krnjaic, Fermilab		The gravitational evidence for the existence of dark matter is overwhelming; observations of galactic rotation curves, the CMB power spectrum, and light element abundances independently suggest that over 80% of all matter is “dark” and beyond the scope of the Standard Model. However, its particle nature is currently unknown, so discovering its potential non-gravitational interactions... More »
July 30, 2018, 2:00 pm US/Central	TBD	Jia Liu, UChicago
Aug. 6, 2018, 2:00 pm US/Central	TBD	Robert Nemiroff, MTU
Aug. 8, 2018, 2:00 pm US/Central	TBD (Note different day)	Francesco Navarro
Aug. 13, 2018, 2:00 pm US/Central	TBD	Asher Berlin, SLAC
Aug. 13, 2018, 2:00 pm US/Central	Massive Gravity and Cosmology	Rachel Rosen, Columbia
Sept. 17, 2018, 2:00 pm US/Central	TBD	Eduardo Rozo, Arizona
Sept. 24, 2018, 2:00 pm US/Central	TBD	Kate Scholberg, Duke
Oct. 1, 2018, 2:00 pm US/Central	TBD	Julian Munoz, Harvard
Oct. 15, 2018, 2:00 pm US/Central	TBD	Yao-Yuan Mao, Pittsburgh
Oct. 29, 2018, 2:00 pm US/Central	TBD	Suzanne Staggs, Princeton
Nov. 5, 2018, 2:00 pm US/Central	Dark matter axion clumps	Mark Hertzberg, Tufts		In this talk I begin by reviewing how dark matter axions can undergo Bose-Einstein condensation and why this is captured by classical field theory. I explain that such condensates are spatially localized clumps, as they are organized by gravitation and self-interactions, and they may populate the galaxy. I discuss both the ground state and finite... More »
Nov. 12, 2018, 2:00 pm US/Central	TBD	Reyco Henning, UNC Chapel Hill
Nov. 19, 2018, 2:00 pm US/Central	TBD	Raymond Co, Michigan
Nov. 26, 2018, 2:00 pm US/Central	TBD	Deanna Hooper, Aachen University	Dan Hooper
Dec. 3, 2018, 2:00 pm US/Central	TBD	Anson Hook, University of Maryland, College Park	Gordan
Dec. 10, 2018, 2:00 pm US/Central	TBD	Hongwan Liu, MIT	TBD
Dec. 17, 2018, 2:00 pm US/Central	TBD	Nilanjan Banik, Amsterdam/Leiden
Feb. 18, 2019, 12:00 pm US/Central	TBA	Ken Van Tilburg, NYU/IAS
Feb. 18, 2019, 2:00 pm US/Central	Cosmic Ray Anti-nuclei and Dark Matter	Ilias Cholis, Oakland University		Antimatter cosmic ray measurements are used to advance our understanding of high energy astrophysical phenomena in the Galaxy. Using the antiproton cosmic ray measurements by the Alpha Magnetic Spectrometer (AMS) onboard the International Space Station, I will present work in search of unexpected sources of antiprotons. I will discuss the uncertainties related to the interstellar... More »
Feb. 25, 2019, 2:00 pm US/Central	TBA	Christine Simpson, University of Chicago (KICP)
March 4, 2019, 2:00 pm US/Central	TBA	Yu-Dai Tsai, Fermilab
March 11, 2019, 2:00 pm US/Central	TBA	Rebecca Leane, MIT
March 25, 2019, 2:00 pm US/Central	TBA	Arran Phipps
April 8, 2019, 2:00 pm US/Central	TBA	Adam Anderson, Fermilab
April 15, 2019, 2:00 pm US/Central	TBA	Kohta Murase, Penn State
April 22, 2019, 2:00 pm US/Central	TBA	Mustafa Amin, Rice University
July 8, 2019, 2:00 pm US/Central	Neutrino Flavor Mixing in Core-Collapse Supernovae	Mackenzie Warren, Michigan State University	Sam McDermott	Core-collapse supernovae, the explosive deaths of massive stars, remain some of the largest computational simulations in astrophysics – requiring careful treatment of general relativity, magento-hydrodynamics, nuclear physics, and neutrino transport and interactions. Despite increasing physical fidelity, modern simulations of core-collapse supernovae still don’t self- consistently account for the effects of neutrino flavor mixing. Such effects... More »
July 15, 2019, 2:00 pm US/Central	Enhancing the Scan Rate of a Dark Matter Axion Search: Quantum Noise Evasion and Maximally Informative Analysis	Daniel Palken, JILA / University of Colorado, Boulder	Gordon Krnjaic	Abstract: Putative axion particles are well motivated solutions to the outstanding mystery of the universe’s dark matter, yet their extremely feeble coupling to ordinary matter makes them difficult to detect. The axion haloscope, first realized experimentally three decades ago, remains among the most viable detection platforms, but even today’s leading technology would take many of... More »
July 22, 2019, 2:00 pm US/Central	Probing Dark Matter and Dark Energy with Strong Gravitational Lensing	Simon Birrer, University of California, Los Angeles	Gordon Krnjaic	Evidence from different cosmological probes have lead to the establishment of the dark matter and dark energy paradigm. Dark matter dominates the matter budget at cosmological scales and drives the formation of structure and dark energy is responsible for the late time acceleration of the universe. In my talk, I will describe how we use... More »
July 29, 2019, 2:00 pm US/Central	The Emerging Population of Gravitational Wave Sources	Will Farr, Stony Brook University / Center for Computational Astrophysics, Flatiron Institute	Gordan Krnjaic	Abstract: The last four years have been a bonanza for gravitational wave astronomy. The first gravitational wave signal ever detected—GW150914, the merger of a 30- and a 40-solar mass black hole—was followed by nine more announced black hole mergers in Advanced LIGO’s first and second observing runs (several were also observed in the Virgo detector). ... More »
Aug. 2, 2019, 2:00 pm US/Central	Pushing Neutrino Physics to the Cosmic Frontier	Mauricio Bustamante, Niels Bohr Institute, University of Copenhagen, Denmark	Gordan Krnjaic	Abstract: There is vast potential in high-energy cosmic neutrinos to test particle physics. The cosmic neutrinos recently discovered by IceCube have the highest detected neutrino energies – up to a few PeV – and travel the longest distances – up to a few Gpc, the size of the observable Universe. These features make them attractive... More »
Aug. 5, 2019, 2:00 am US/Central	Pulsar Timing as a Probe of Primordial Black Holes and Subholes	Jeff Dror, Lawrence Berkeley National Laboratory	Gordon Krnjaic	Abstract: Pulsars act as accurate clocks, sensitive to gravitational redshift and acceleration induced by transiting clumps of matter. In this talk, I study the sensitivity of pulsar timing arrays (PTA) to transiting compact dark matter objects, focusing on primordial black holes and subhalos. Such dark matter clumps can result in different classes of signals observable in pulsar timing experiments depending on the... More »
Aug. 12, 2019, 2:30 pm US/Central	Multiwavelength Dark Matter Searches	Tesla Profumo, University of California, Santa Cruz		The nature of the dark matter particle and what underlying particle physics model it relates to remain unknown. I will describe multi-pronged, astronomical investigations of both WIMP and non-WIMP dark matter candidates using radio, X-ray, and gamma-ray data. These studies include tests of the potential dark matter origin of galactic gamma-ray signals in our Galaxy... More »
Aug. 19, 2019, 2:00 pm US/Central	Axion Dark Matter Detection with CMB Polarization	Michael Fedderke, Stanford University / University of California - Berkeley / LBNL	Gordon Krnjaic	Abstract: In this talk, I will detail two ways to search for low-mass axion dark matter using cosmic microwave background (CMB) polarization measurements. These appear, in particular, to be some of the most promising ways to directly detect fuzzy dark matter. Axion dark matter causes rotation of the polarization of light passing through it. This... More »
Aug. 20, 2019, 2:00 pm US/Central	TeV Dark Matter Search Program with the Cherenkov Telescope Array: The Strategy and Synergies with Current Gamma-Ray Experiments	Gabrijela Zaharijas, Univ. of Nova Gorica, Slovenia		Abstract: High-energy gamma rays are among the most promising tools to constrain or reveal the nature of dark matter, in particular the Weakly Interacting Massive Particles (WIMP) models. The Cherenkov Telescope Array (CTA) is well into its pre-construction phase and will soon probe the high-energy gamma-ray sky in the 20 GeV – 300 TeV energy range. Thanks... More »
Aug. 26, 2019, 2:00 pm US/Central	Baryogenesis and Dark Matter from B Mesons	Miguel Escudero Abenza, King's College London		In this talk, based on arXiv:1810.00880, I will present a new mechanism of Baryogenesis and dark matter production in which both the dark matter relic abundance and the baryon asymmetry arise from neutral B meson oscillations and subsequent decays. In the early Universe, decays of a long lived particle produce B mesons and anti-mesons out... More »
Sept. 9, 2019, 2:00 pm US/Central	A 1700 km/s Hyper Velocity Star discovered by the Southern Stellar Stream Spectroscopic Survey	Ting Li, Carnegie Observatories		In this talk, I will present an ongoing spectroscopic program, the Southern Stellar Stream Spectroscopic Survey (S5), which maps these southern streams with the fiber-fed AAOmega spectrograph on the Anglo-Australian Telescope. S5 is the first systematic program pursuing a complete census of known streams in the southern hemisphere. In additional to observing stars in the... More »
Sept. 16, 2019, 2:00 pm US/Central	Machine Learning Dark Matter Halo Formation	Luisa Lucie-Smith, University College London		Dark matter halos are the fundamental building blocks of cosmic large-scale structure. Improving our theoretical understanding of their structure, evolution and formation is an essential step towards understanding how galaxies form. Although N-body simulations are the only tool to fully compute the non-linear gravitational evolution of halos, it is difficult to gain physical interpretation from... More »
Sept. 23, 2019, 2:00 pm US/Central	Searching for Quantum Structures in Axion Dark Matter	Erik Lentz, Georg-August Universitaet Goettingen		Axions and axion-like particles are becoming increasingly attractive candidates for the dark matter. Likewise, searches for these candidates are growing in sophistication, number, reach, and may span much of the candidates’ viable parameter space in the next decade. Many of these searches are capable of extracting detailed knowledge of the local axion distribution, and may... More »
Sept. 30, 2019, 2:00 pm US/Central	Toward the Future of Gravitational-Wave Cosmology and More	Hsin-Yu Chen, Harvard University		Advanced LIGO-Virgo have detected tens of stellar mass compact binary mergers, including binary black holes, binary neutron stars, and potentially neutron star-black hole mergers. In this talk I will focus on a few topics we can learn from these binary mergers: the electromagnetic counterparts of gravitational-wave events, the nuclear equation-of-state, and cosmology. I will first... More »
Oct. 9, 2019, 2:00 pm US/Central	Measuring the Hubble Constant using Strongly Lensed Quasars	Anowar Shajib, UCLA		The recent tension between early- and late-Universe measurements of the Hubble constant highlights the necessity for independent and precise methods such as the time-delay cosmography. The measured time-delays between the lensed images of a background quasar depend on the absolute physical scales in the lens configuration. Thus, the time-delays allow measurements of these scales to infer... More »
Oct. 14, 2019, 2:00 pm US/Central	Signatures of the Early Universe in the BAO Spectrum	Benjamin Wallisch, UC-San Diego		Abstract: Due to theoretical developments and an increase in survey sensitivity, these measurements can now be complemented by large-scale structure observations. In this talk, I will advocate the spectrum of baryon acoustic oscillations (BAO) as a new observable for early universe cosmology beyond its use as a standard ruler. I will present the first measurement... More »
Oct. 17, 2019, 1:00 pm US/Central	Exceptionally Heavy Dark Matter	Nadav Outmezguine, Tel-Aviv University		Abstract: In models where dark matter relic abundance is set by standard thermal freeze-out mechanism, perturbative unitarity bounds require its mass to be below few hundreds TeV. We propose a new thermal freeze-out mechanism, resulting in dark matter mass up to roughly a million TeV, without violating unitarity bounds and without modifying the standard cosmological history.
Oct. 21, 2019, 3:00 pm US/Central	Making Dark Matter out of Light: The Cosmology of sub-MeV Freeze-In	Katelin Schutz, Massachusetts Institute of Technology		Dark matter could be a “thermal-ish” relic of freeze-in, where the dark matter is produced by extremely feeble interactions with Standard Model particles dominantly at low temperatures. In this talk, I will discuss how sub-MeV dark matter can be made through freeze-in, accounting for a dominant new channel where the dark matter gets produced by... More »
Oct. 28, 2019, 2:00 pm US/Central	The Future of Massively Multiplexed Spectroscopy: The Maunakea Spectroscopic Explorer	Jennifer Marshall, Texas A&M University		Results from modern wide-field astronomical imaging surveys have highlighted the need for large aperture, massively multiplexed spectroscopic followup facilities in the optical and near-Infrared wavelength regimes. Such a facility is the most obvious missing link in the emerging network of ground-based observational facilities world-wide. The Maunakea Spectroscopic Explorer (MSE) is a planned 11-m telescope facility... More »
Nov. 4, 2019, 2:00 pm US/Central	Diversity in Density Profiles of Self-Interacting Dark Matter Satellite Halos	Chih-Liang Wu, Massachusetts Institute of Technology		Self-interacting Dark Matter (SIDM) could have a number of striking observable effects, including modifications to the dark matter density on sub-galactic scales. Recent studies have revealed both ultra-compact and ultra-diffuse satellite dwarf galaxies within the Milky Way; I will show that tidal stripping of SIDM satellite halos naturally leads to a wider range of halo... More »
Nov. 11, 2019, 2:00 pm US/Central	Conformal Freeze-In	Sungwoo Hong, Cornell University		Conventionally, the main focus for the cosmic evolution of our universe has been on descriptions in terms of particles: dark matter (DM) as massive particle, and dark radiation, if existing at all, in the form of massless or very light particle. In this talk, I will discuss a scenario where conformal field theory (CFT) plays... More »
Nov. 18, 2019, 2:00 pm US/Central	The Accelerated Universe through Weak Lensing	Agnès Ferté, Jet Propulsion Laboratory / California Institute of Technology		The universe has been going through a phase of accelerated expansion for the last 6 billion years. Understanding the origin of this cosmic acceleration is one of the main goals of observational cosmology: is it caused by a cosmological constant or a dynamical dark energy? Or is it a sign that we don’t understand the... More »
Nov. 25, 2019, 2:00 pm US/Central	The Trouble with Hubble: Signs of New Physics?	Vivian Poulin, LUPM (CNRS & Université de Montpellier)		The value of the Hubble constant as measured using the classical distance ladder method is 4 to 6 sigma higher than the value inferred from a ΛCDM fit to the cosmic microwave background (CMB). Interestingly, we now have several independent local probes of the Hubble constant (supernovae, strongly lensed quasars), such that none of the... More »
Dec. 2, 2019, 2:00 pm US/Central	Redshift Inference from the Combination of Galaxy Colors and Clustering in a Hierarchical Bayesian Model	Alex Alarcon, Argonne National Laboratory		Photometric galaxy surveys constitute a powerful cosmological probe but rely on the accurate characterization of their redshift distributions using only broadband imaging, and can be very sensitive to incomplete or biased priors used for redshift calibration. Several techniques for estimating the redshift distributions of imaging surveys have been developed in the last decades, which can... More »
Dec. 9, 2019, 2:00 pm US/Central	Early-Universe Simulations of the Cosmological Axion	Malte Buschmann, University of Michigan		Abstract: Ultracompact dark matter (DM) minihalos at masses at and below 10^−12 solar masses arise in axion DM models where the Peccei-Quinn (PQ) symmetry is broken after inflation. The minihalos arise from density perturbations that are generated from the non-trivial axion self interactions during and shortly after the collapse of the axion-string and domain-wall network.... More »
Dec. 16, 2019, 2:00 pm US/Central	Particle Acceleration in the Cygnus Star Forming Region	Binita Hona, Michigan Technological University		Massive stars were postulated as sources of cosmic rays (CRs) in our Galaxy since more than three decades ago. GeV photons have been observed by Fermi-LAT from the star-forming region of Cygnus X, showing that young CRs up to TeV are produced and are interacting with the ambient gas and radiation fields. However, the role... More »
Jan. 13, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: Leak-In Dark Matter	Cristian Gaidau, University of Illinois		I will discuss leak-in dark matter, a novel out-of-equilibrium origin for the dark matter (DM) in the universe. Leak-in DM is a minimal, internally-thermalized, hidden sector populated from an out-of-equilibrium, feeble connection to the hotter standard model (SM) sector. When this connection is renormalizable, the colder sector undergoes an extended phase of non-adiabatic evolution largely... More »
Jan. 27, 2020, 3:00 pm US/Central	Particle Astrophysics Seminar: Time-Domain Astrophysics in a Multi-Messenger World	Kate Alexander, Northwestern University		Time-domain astrophysics provides a unique opportunity to study the most extreme physical processes in the Universe, including the deaths of massive stars, the destruction and creation of compact objects like neutron stars and black holes, and the tidal disruption of stars by supermassive black holes. Recently, with the pioneering detections of gravitational waves, astronomers and... More »
Feb. 3, 2020, 1:00 pm US/Central	Particle Astrophysics Seminar: The Inflaton Portal to a Highly Decoupled EeV Scale Dark-Matter: Production Mechanism and Experimental Signatures	Lucien Heurtier, University of Arizona		In this talk, I will explore the possibility that the dark matter relic abundance is generated in a context where the inflaton is the only mediator between the visible and the hidden sectors of our Universe. I will present a model of highly-decoupled dark matter and show that involving the inflationary sector in the mechanism... More »
Feb. 3, 2020, 2:00 pm US/Central	Superradiance Inferences from Black Holes Spins Measured by LIGO and X-Ray Binaries	Nicolas Fernandez Gonzalez, University of Illinois (Urbana-Champaign)		Black holes are the perfect playground for physics, to search for new ultralight bosons. Bosons can form clouds around rotating black holes if their Compton wavelength is comparable to the black hole size, through a process called superradiance, extracting angular momentum and energy from the black hole and populating an exponentially large number of gravitationally-bound... More »
Feb. 10, 2020, 2:00 pm US/Central	Superradiance Inferences from Black Holes Spins Measured by LIGO and X-Ray Binaries	Nicolas Fernandez Gonzales, University of Illinois		Black holes are the perfect playground for physics, to search for new ultralight bosons. Bosons can form clouds around rotating black holes if their Compton wavelength is comparable to the black hole size, through a process called superradiance, extracting angular momentum and energy from the black hole and populating an exponentially large number of gravitationally-bound... More »
Feb. 17, 2020, 2:00 pm US/Central	Cosmological Constraints with Clusters from the SPT-SZ and SPTpol Extended Cluster Surveys	Lindsey Bleem, Argonne National Laboratory		Clusters of galaxies selected by the Sunyaev-Zel’dovich (SZ) effect are powerful tools with which to constrain cosmological models. Here I will present the latest cosmological results using clusters identified by the South Pole Telescope (SPT) particularly focusing on results from the 2500 deg^2 SPT-SZ and new 2700 deg^2 SPTpol Extended Cluster Survey (SPT-ECS); with the... More »
Feb. 24, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: Classifying High-redshift Merging Galaxies with Deep Neural Networks	Aleksandra Ćiprijanović, Mathematical Institute of the Serbian Academy of Sciences and Arts		Abstract: Distinguishing between merging and non-merging galaxies in observations can sometimes be a very slow and difficult process. Today, with the availability of large-scale simulations, we have the ability to learn from large samples of labeled images of merging galaxies and transfer that knowledge to search for these objects in the observed data. The task of... More »
March 2, 2020, 2:00 pm US/Central	Light Relics in Cosmic Microwave Background	Marilena Loverde, Stony Brook University		Neutrinos and other light relic particles leave a number of imprints in the cosmic microwave background anisotropies and on maps large-scale structure of the universe. Some of these imprints can not only demonstrate the presence of these particles, but can provide insight into their nature via signatures of interactions or other behavior that changes during... More »
March 9, 2020, 2:00 pm US/Central	Searching for Dark Matter with Liquid Scintillators	Benjamin Lillard, University of Illinois (Urbana-Champaign)		Organic scintillators are a promising and under-developed avenue for the direct detection of sub-GeV dark matter through electron scattering. With eV-scale excitation energies that rival the sensitivity of semiconductor targets, they can be produced in bulk quantities and purified relatively inexpensively. A low-background kilogram-size liquid scintillator target could achieve world-leading sensitivity to sub-GeV dark matter... More »
March 16, 2020, 2:00 pm US/Central	Large-Scale Structure Cosmology with AI-Accelerated Forward Modeling	Andrew Hearin, Argonne National Laboratory		Present-day and near-future galaxy surveys create the capability to measure cosmological structure growth using multiple, distinct populations of galaxies as tracers of the underlying density field. Multi-tracer cross-correlations contain rich information that can be used to self-calibrate systematics and significantly enhance cosmological constraining power. However, conventional theoretical models for making these predictions bear the mark... More »
March 23, 2020, 2:00 pm US/Central	A New Mask for An Old Suspect: Testing the Sensitivity of the Galactic Center Excess to the Point Source Mask	Yiming Zhong, UChicago		The Fermi-LAT collaboration has recently released a new point source catalog, referred to as 4FGL. For the first time, we perform a template fit using information from this new catalog and find that the Galactic center excess is still present. On the other hand, we find that a wavelet-based search for point sources is highly... More »
March 30, 2020, 2:00 pm US/Central	CrystaLiZe: A Solid Future for LZ	Scott Kravitz, Lawrence Berkeley National Laboratory		Radon and its daughter decays limit the sensitivity of direct WIMP dark matter searches, despite extensive screening programs, careful material selection and specialized Rn-reduction systems. For xenon time projection chambers, a means to surpass this constraint may lie in crystallizing the xenon. In a solid matrix, each of the decay steps surrounding the problematic radon... More »
April 13, 2020, 1:00 pm US/Central	Particle Astrophysics Seminar: Dark matter from scalar field fluctuations	Tommi Tenkanen, Johns Hopkins University		Abstract: The observed dark matter (DM) abundance in the Universe can be fully accounted for by a minimally coupled spectator scalar field that was light during cosmic inflation. In this scenario, dark matter was produced during inflation by amplification of quantum fluctuations of the spectator field. I will discuss the DM isocurvature perturbations that are... More »
April 20, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: Primordial Black Hole Dark Matter and Ways to Find It	Volodymyr Takhistov, UCLA		Abstract: Primordial black holes (PBHs) constitute an attractive candidate for dark matter. I will describe a new generic mechanism for PBH formation from fragmentation of scalar fields, which allows to produce PBHs with high spin. I will then revisit another general formation mechanism, from vacuum bubbles during inflation, and show how the resulting broad PBH... More »
April 27, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: Talks, sure, but how? Making the case for prerecorded science talks.	Knud Jahnke, Max Planck Institute for Astronomy		For more information, please join the FCPA mailing list.
May 4, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: New Channels in the Search for Dark Matter	Daniel Baxter, University of Chicago		Abstract: In direct detection experiments, interpreting an observed rate as a limit on (or detection of) dark matter requires assumptions about the type of interaction. Typically, this breaks down as elastic nuclear scattering (for energies >1 keV) or electron scattering (for energies 1-50 eV). The first challenge to this conventional way of thinking came in... More »
May 11, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: Strongly Interacting Dark Matter	Hitoshi Murayama, Berkeley		Abstract: Dark Matter may not be an elementary particle but rather bound states of strong interactions similar to hadrons in QCD. It is actually desirable if we want dark matter to be self-interacting to address the core/cusp issue. It could be dark pions that undergo freeze-out by 3->2 annihilation. It could also be dark baryons that... More »
May 18, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: The bright future of cosmology with SPT-3G	Amy Bender, Argonne National Laboratory		Abstract: Observations of the cosmic microwave background (CMB) probe a diverse set of fundamental physics in both the early and late universe. CMB measurements are a cornerstone of our now exceptionally precise Lambda-CDM model of cosmology, however, many questions remain. Did an inflationary epoch occur a fraction of a second after the Big Bang? What... More »
June 1, 2020, 11:00 am US/Central	Particle Astrophysics Seminar: Cosmic discordances	Eleonora Di Valentino, University of Manchester		Abstract: The Cosmic Microwave Background (CMB) temperature and polarization anisotropy measurements from the Planck mission have provided strong confirmation of the LCDM model of structure formation. However, there are a few interesting tensions with other cosmological probes and anomalies in the data that leave the door open to possible extensions to LCDM. The most famous... More »
June 8, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: The rise and fall of spectroscopy in weak lensing experiments	Will Hartley, Geneva University		Abstract: A measurement of the parameters that governing the expansion history of the universe via weak gravitational lensing requires two key ingredients: a two-point function of galaxy shape measurements and the redshift distributions of the galaxy samples involved in the analysis. As weak lensing surveys grew in statistical precision, the demand for improved redshift estimates... More »
June 15, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: The Renaissance of Astro-Physics: a landscape of opportunities in the era of Time Domain Multi-Messenger investigations	Raffaella Margutti, Northwestern		Abstract: Astronomical transients are signposts of catastrophic events in space where physics happens at conditions not testable on earth, including the most extreme stellar deaths, stellar tidal disruptions by supermassive black holes, and mergers of compact objects. Thanks to new and improved observational facilities we can now sample the night sky with unprecedented temporal cadence... More »
June 22, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: Axion dark matter and dark energy detection	Peter Graham, Stanford		Abstract: If dark energy is not a cosmological constant but in fact dynamical, it is natural for it to have axion-like couplings to Standard Model particles. It is then in principle possible to do direct detection of dark energy in a laboratory experiment. We found a technique using proton storage ring experiments that could have... More »
June 29, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: Optical Cosmic Survey at the Low Surface Brightness limit: Detection of Diffuse Light in Galaxies and Galaxy Clusters	Yuanyuan Zhang, FNAL		Abstract: The enormous amount of data collected by DES provides a great opportunity to explore low surface brightness science, such as faint diffuse light in galaxies and galaxy clusters. Through stacking the images of ~300 galaxy clusters from the Dark Energy Survey, we report the detection of diffuse intra-cluster light beyond a surface brightness limit... More »
July 6, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: New Avenues of Thermal Dark Matter	Juri Smirnov, OSU		Abstract: For dark matter models, thermal production mechanisms are highly predictive frameworks. Charting possible realizations is important, as it leads to insights that guide experimental efforts to fully test particle dark matter. I will discuss how new non-perturbative effects, such as bound-state formation, can affect the thermal relic abundance and lead to new detectable signatures.... More »
July 13, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: High Redshift Supernovae: Beyond The Epoch of Dark Energy	Lou Strolger, STScI		Abstract: For nearly two decades the Hubble Space Telescope has been heavily used to locate supernovae in high redshift environments, with the primary goal of improving constraints on the nature of dark energy. Along the way we have made observations on the nature of supernovae themselves, and clues to their elusive progenitor mechanisms. From complete... More »
July 27, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: Tracing Dark Matter with Stars	Lina Necib, Caltech		Abstract: In this talk, I explore the impact of stellar kinematics on understanding the particle nature of Dark Matter in three separate locations: the solar neighborhood, the Galactic center, and dwarf galaxies. I first discuss the implications of the different stellar components on direct detection experiments. I show how to use the velocity distribution of... More »
Aug. 3, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: Dark Matter Throughout Cosmic History	Vera Gluscevic, USC		Abstract: Dark matter constitutes 85% of matter content in the Universe, but its physical nature remains unknown and requires new physics to explain. I will review the status of cosmological searches for dark matter interactions, summarizing the best current limits on scattering of light particle candidates with protons derived from the cosmic-microwave-background anisotropy measurements. I... More »
Aug. 10, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: Hidden Signals in a Population of Galaxy Clusters	Arya Farahi, University of Michigan		Abstract: Galaxy-clusters (clusters) are the most massive gravitationally collapsed structures in the Universe. It is established that, on average, the observables of clusters scale with their mass. This scaling relation has been successfully capitalized to constrain the cosmological parameters. Each cluster was formed at a different time and experienced a different formation history. Additionally, their... More »
Aug. 17, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: Challenges and opportunities of photometric reshift surveys	David Alonso, Oxford		Abstract: Imaging surveys, such as the Dark Energy Survey, the Kilo-Degree Survey, the Hyper Suprime-Cam and, in the near future, the LSST at the Rubin Observatory and the Euclid space mission, constitute a powerful tool to constrain the expansion and growth history of the Universe at late times. Their cross-correlation with other observables, such as... More »
Aug. 24, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: PUMA: the next generation intensity mapping experiment	Anze Slosar, BNL		Abstract: Universe is full of neutral hydrogen shining in the 21-cm spin-flip transition. Using this line to trace cosmic structure allows us to map the large scale structure in three dimensions very fast and cost efficiently. Realizing the potential of this technique in pracice has proven to be devilishly difficult. Fortunately, the problems are purely... More »
Aug. 31, 2020, 2:00 pm US/Central	Particle Astrophysics Seminar: Weak lensing with the Dark Energy Survey	Alexandra Amon, Stanford		Abstract: I will present the current status of the cosmological weak lensing analysis from the Dark Energy Survey (DES) using its first three years of data, taken using the Dark Energy Camera on the 4m Blanco telescope at CTIO. This analysis spans the full DES footprint, over 4000 sq. deg. of sky, with the final... More »
Sept. 14, 2020, 2:00 pm US/Central	CPC Seminar: Intergalactic Medium-based Cosmology in the era of DESI	Satya Gontcho A Gontcho, U Rochester		Abstract: Intergalactic Medium (IGM)-based cosmology established itself as a solid cosmological probe with the wide success of the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), and now recently reconfirmed with the SDSS-IV extended-BOSS (eBOSS). With the Dark Energy Spectroscopic Instrument (DESI) survey officially built and imminently resuming operations, we are taking a look at the accomplishments... More »
Sept. 21, 2020, 2:00 pm US/Central	CPC Seminar: Gravitational Laboratories for Nuclear Physics	Reed Essick, U Chicago		Abstract: Gravitational waves provide a completely new way to study the universe. From the initial direct detection of coalescing black holes in 2015, to the ground-breaking multimessenger observations of coalescing neutron stars in 2017, and continuing with the now routine detection of merging stellar remnants, gravitational wave astronomy has quickly matured into a key aspect... More »
Sept. 28, 2020, 2:00 pm US/Central	CPC Seminar: Clocking the formation of local Brightest Cluster Galaxies	Louise Edwards, Cal Poly		Abstract: Several puzzles continue to plague our understanding of the formation of Brightest Cluster Galaxies (BCGs): 1) What can the age and metallicity of the accumulated stellar mass tell us about when, where and how BCGs are created – and can these be understood simultaneously in hierarchical galaxy formation models? 2) How does the intracluster... More »
Oct. 5, 2020, 4:30 pm US/Central	CPC Seminar: Gravitational microlensing with extended dark matter structures	Djuna Croon, TRIUMF		Abstract: Many models of dark matter feature small scale substructure. In this talk, I will describe how gravitational microlensing provides stringent constraints on such models. In particular, I will explain how existing techniques used to probe point-like objects (such as primordial black holes and MACHOs) can be adapted to find constraints on several different extended... More »
Oct. 12, 2020, 4:00 pm US/Central	CPC Seminar: The Primordial Black Holes Variations	Stefano Profumo, UCSC		Abstract: In the age of gravitational wave astronomy, the possibility that some of the black holes in the universe have a primordial, rather than stellar origin, and that they might be a non-negligible fraction of the cosmological dark matter, is quite intriguing. I will review the status of the field, and comment on search strategies... More »
Oct. 19, 2020, 3:00 pm US/Central	CPC Seminar: Gravitational waves from phase transitions: clearing the path between theory and experiment	Graham White, IPMU		Abstract: Next generation gravitational wave detectors have a chance of verifying the existence of a cosmological first order transition. To make quantitative statements requires a proper understanding of the process of taking a model with a given set of parameters, converting those parameters into macroscopic thermal parameters and converting those thermal parameters into observables. In... More »
Oct. 26, 2020, 2:00 pm US/Central	CPC Seminar: The gravitational wave universe through the lens	Jose Maria Ezquiaga Bravo, U Chicago		Abstract: The discovery of strong gravitational lensing of gravitational waves (GWs) would represent a major advance in astronomy. Assessing the probability that two or more events are lensed images of the same source requires a good understanding of the properties of the lensed images. In this talk I will discuss the key role of lensing... More »
Nov. 2, 2020, 2:00 pm US/Central	CPC Seminar: Probing cosmology using dark matter microhalos	Stan Delos, UNC		Abstract: Through their observable properties, the first and smallest dark matter halos represent a rare probe of subkiloparsec-scale variations in the density of the early Universe. These density variations could hold clues to the nature of inflation, the postinflationary cosmic history, and the identity of dark matter. However, the dynamical complexity of these microhalos hinders... More »
Nov. 9, 2020, 2:00 pm US/Central	CPC Seminar: AGN disks have THINGS in them--and those things are important	Saavik Ford, CUNY/AMNH		Abstract: Active Galactic Nuclei (AGN) have usually been modeled and conceptualized solely in terms of their gas content. However, given the existence of Nuclear Star Clusters (NSCs) it is reasonable to expect stars and stellar remnants will also exist in AGN disks. Their presence leads to several important consequences, notably the AGN-driven channel for mergers... More »
Nov. 16, 2020, 2:00 pm US/Central	CPC Seminar: Resonant Self-Interacting Dark Meson and Smale-Scale Observations	Yu-Dai Tsai, FNAL		Abstract: In this talk, we discuss a series of models that can explain the small-scale observations (potential tensions between cold dark matter simulation and observation). We also discuss the astrophysical studies to test them. We present models of resonant self-interacting dark matter in a dark sector with QCD, based on analogies to the meson spectra... More »
Nov. 23, 2020, 2:00 pm US/Central	CPC Seminar: The Hubble Tension and Early Dark Energy	Marc Kamionkowski, JHU		Abstract: We’ve known since the late 1920s that the Universe is expanding. However, the expansion rate currently inferred from measurements of the cosmic microwave background now disagrees with that obtained from supernova measurements. Over the past few years, theorists have been exploring the possibility that this Hubble tension is explained by some new “early dark... More »
Nov. 30, 2020, 2:00 pm US/Central	CPC Seminar: : New Pathways to the Relic Abundance of Vector-Portal Dark Matter	Patrick Fitzgerald, MIT		Abstract: In the conventional weakly-interacting massive particle (WIMP) paradigm the late-time density of dark matter (DM) is set by the rate of two-body annihilations, but there has been considerable recent interest in exploring alternative DM scenarios where other interactions control the final abundance. I will show that by fully exploring the parameter space of a... More »
Dec. 7, 2020, 2:00 pm US/Central	CPC Seminar: Cosmology with weak lensing in ongoing and upcoming imaging surveys	Rachel Mandelbaum, CMU		Abstract: Weak gravitational lensing is one of the most sensitive probes of the growth of structure in the Universe, and is therefore a key part of the cosmological community’s program for understanding the nature of dark energy. It is also a powerful probe of the connection between the visible components of galaxies and galaxy clusters,... More »
Dec. 14, 2020, 2:00 pm US/Central	CPC Seminar: Prospects for Axion Detection with the Princeton Comagnetometer Experiment	Mariangela Lisanti, Princeton		Abstract: Noble-alkali comagnetometers offer the exciting possibility of detecting the anomalous magnetic fields sourced by ultralight axion-like particles. I will discuss an on-going reanalysis of data from a helium-potassium comagnetometer at Princeton, which is expected to yield world-leading sensitivity to axion-neutron couplings in the mass range from to eV. This analysis requires a careful treatment... More »
Feb. 1, 2021, 2:00 pm US/Central	CPC Seminar: Insights on galaxy evolution and morphology from deep learning	John Wu, Space Telescope Science Institute		Abstract: The growth of galaxies is regulated by the amount of cold gas available to form stars. In order to constrain galaxy evolution models, it is critical to measure the interstellar gas mass and the abundance of heavy elements (metallicity) in the gas phase for large samples of galaxies. However, these properties are observationally difficult... More »
Feb. 8, 2021, 9:30 am US/Central	CPC Seminar: The fate of hints: recent developments in neutrino phenomenology	Thomas Schwetz-Mangold, KIT		Abstract: Finite neutrino mass points to new physics beyond the Standard Model. In this talk I give an overview over recent results in neutrino physics, including the results of a combined analysis of latest neutrino oscillation data. We comment on the implications of last years results for the type of neutrino mass ordering (normal versus... More »
Feb. 15, 2021, 2:00 pm US/Central	CPC Seminar: Knocking on the doors of dusty giants in the Universe	Darko Donevski, SISSA - Italy		Abstract: Since their initial discovery 20 years ago, very distant and massive galaxies that form prodigious amount of young stars – so-called dusty, star-forming galaxies – represent a serious challenge for the theory of galaxy formation. On the one hand, they are difficult to detect because they reside in dense regions of the distant Universe... More »
Feb. 22, 2021, 2:00 pm US/Central	CPC Seminar: Merging deep learning with physical models for the analysis of modern cosmological surveys	Francois Lanusse, CEA - France		Abstract: The upcoming generation of cosmological surveys such as LSST will aim to map the Universe in great detail and on an unprecedented scale. This of course implies new and outstanding challenges at all levels of the scientific analysis, from pixel level data reduction to cosmological inference. In this talk, I will illustrate how recent... More »
March 1, 2021, 2:00 pm US/Central	CPC Seminar: Multi-messenger studies of binary stellar systems with the SKA	Tana Joseph, U of Manchester		Abstract: The discovery of gravitational waves has opened up a new window in multi-messenger astronomy. When used in combination with traditional electromagnetic signals and other messenger particles like cosmic rays, meteorites and neutrinos, we are able to study the Universe like never before. The Square Kilometre Array (SKA) and its precursors, MeerKAT and ASKAP, can... More »
March 8, 2021, 2:00 pm US/Central	CPC Seminar: Nearest neighbor distributions: New statistical measures for cosmological clustering	Arka Banerjee, Fermilab		Abstract: The two-point correlation function, or the power spectrum, is the most widely used statistical tool to summarize clustering in the data for cosmological analyses. While the two-point function is a complete statistical description for a Gaussian random field, it does not capture all the information for strongly nonlinear fields relevant for cosmology at low... More »
March 15, 2021, 2:00 pm US/Central	CPC Seminar: Discovering new physics in the era of black holes	Ben Lehmann, UCSC		Abstract: The future is now: black holes are routinely measured by gravitational wave observatories, pulsar timing arrays see hints of a stochastic gravitational wave background, and LISA is slated to launch in the next decade. Black holes are quickly becoming a major driver of developments in astrophysics and cosmology. The ongoing challenge, however, is to... More »
March 22, 2021, 2:00 pm US/Central	CPC Seminar: Phenomenology of Magnetic Black Holes	Nicholas Orlofsky, Carleton University		Abstract: Magnetically charged black holes are interesting solutions of the Standard Model and general relativity. They may possess a “hairy” electroweak-symmetric corona outside the event horizon, which speeds up their Hawking radiation and leads them to become nearly extremal on short timescales. Their masses could range from the Planck scale up to the Earth mass.... More »
March 29, 2021, 2:00 pm US/Central	CPC Seminar: Discovering New Physics with Cosmological Data Sets	Cora Dvorkin, Harvard U		Abstract: Measurements of the Cosmic Microwave Background and the large-scale structure of the universe have made it possible to determine with great precision the universe’s inventory, as well as properties of its initial conditions. However, there are profound questions that remain unanswered.Cosmological observations and galaxy dynamics seem to imply that 84% of all matter in... More »
April 5, 2021, 2:00 pm US/Central	CPC Seminar: From Asteroids to Black Holes: Data Science for Next-Generation Time Domain Astronomy	Daniela Huppenkoten, SRON - Netherlands		Abstract: Across almost all scientific disciplines, the instruments that record our experimental data and the methods required for storage and data analysis are becoming increasingly sophisticated. This has been particularly true for astronomy, where current instruments like NuSTAR and ZTF, and future telescopes like the Rubin Observatory and Athena produce data sets of a size... More »
April 12, 2021, 2:00 pm US/Central	CPC Seminar: Directional dark matter detection and the CYGNUS project	Ciaran O'Hare, University of Sydney		Abstract: The last few years has seen the largest underground dark matter searches rapidly approach their purported ultimate sensitivity limit, the so-called “neutrino floor”. An experiment reaches the neutrino floor went it becomes so large and so sensitive that the background from coherent nuclear scattering of astrophysical neutrinos starts to drown out a potential dark... More »
April 19, 2021, 2:00 pm US/Central	CPC Seminar: The Tiny (g-2) Muon Wobble from Small-μ Supersymmetry	Carlos Wagner, Argonne		Abstract: A new measurement of the muon anomalous magnetic moment has been recently reported by the Fermilab Muon g-2 collaboration and shows a 4.2σ departure from the most precise and reliable calculation of this quantity in the Standard Model. Assuming that this discrepancy is due to new physics, I will discuss its relation with other... More »
April 26, 2021, 2:00 pm US/Central	CPC Seminar: Minding the Gap: Lessons from LIGO-Virgo’s Biggest Black Holes	Maya Fishbach, Northwestern/CIERA		Abstract: Stellar theory predicts the existence of a black hole mass gap in the range ~50 to ~120 solar masses resulting from pair instability supernovae. The binary black holes of LIGO-Virgo’s first two observing runs supported this prediction, showing evidence for a dearth of component black hole masses above 45 solar masses. Meanwhile, among the... More »
May 3, 2021, 2:00 pm US/Central	CPC Seminar: Dark matter and neutrino decays with line-intensity mapping	José Luis Bernal,, John Hopkins		Abstract: Line-intensity mapping (LIM) experiments use the integrated intensity at a given frequency, targeting well-known spectral lines to infer the redshift of the signal and build three-dimensional maps of cosmic volumes. Since these surveys exploit the information from all incoming photons, they have the potential to directly observe the electromagnetic radiation produced in exotic radiative... More »
May 10, 2021, 2:00 pm US/Central	CPC Seminar: Baryonic effects in the Effective Field Theory of Large-Scale Structure and an analytic recipe for lensing in CMB-S4	Matthew Lewandowski, Northwestern		Abstract: Upcoming Large-Scale Structure surveys will likely become the next leading sources of cosmological information, making it crucial to have a precise understanding of the influence of baryons on cosmological observables. The Effective Field Theory of Large-Scale Structure (EFTofLSS) provides a consistent way to predict the clustering of dark matter and baryons on large scales,... More »
May 17, 2021, 2:00 pm US/Central	CPC Seminar: Deciphering the Biography of Massive Stars: Compact Object Mergers as a Rosetta Stone	Michael Zevin, UChicago		Abstract: The LIGO—Virgo Collaboration has now announced 50 confident detections of gravitational waves from compact object mergers. These novel observations encode important information about their progenitor stellar systems, such as the types of galactic environments they were born in, the intricacies of stellar evolution that persisted throughout their lives, and the physics of the supernovae... More »
May 24, 2021, 2:00 pm US/Central	CPC Seminar: Using Machine Learning to Prepare for Photometric Supernova Cosmology with Rubin Observatory LSST	Kara Ponder, SLAC		Abstract: The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) will produce 10 million transient notifications per night and will observe 100,000s of supernovae over 10 years. Spectroscopic resources will not be able to keep up with the demand for classifications of these objects. In this talk, I will present ways that... More »
June 7, 2021, 2:00 pm US/Central	CPC Seminar: Searches for High-Energy Neutrinos from the Sun	Jeffrey Lazar, Harvard		Abstract: While the Sun has already proved a fruitful laboratory for neutrino physics, high-energy solar neutrinos may continue to provide insight. For example, current-generation neutrino telescopes have searched for an excess of neutrinos from the Sun’s direction as evidence of annihilating weakly interacting massive particles (WIMPs) at energies from ~0.1 GeV to 10^4 GeV. Detection... More »
June 21, 2021, 4:00 pm US/Central	CPC Seminar: Characterizing galaxy merger remnants with photometry and kinematics	Connor Bottrell, Kavli IPMU		Abstract: As observed triggers of starbursts, active galactic nuclei, and the energetic feedback produced by these phenomena, galaxy mergers are uniquely poised to examine some of the most crucial ingredients of galaxy formation and evolution. Spectroscopic studies of galaxy pairs have shed light on the role of mergers in driving the ex-situ build-up of stellar... More »
June 28, 2021, 2:00 pm US/Central	CPC Seminar: How do we best identify merging galaxies? Expanding the toolkit to include stellar kinematics and JWST NIRCam imaging	Rebecca Nevin, Harvard		Abstract: The difficulty of accurately identifying galaxy mergers, let alone classifying galaxy mergers of different mass ratios and stages, limits our understanding of the contribution of mergers to galaxy evolution. In recent years, machine learning has emerged as an exciting new avenue to increase the accuracy, completeness, and precision of merger identification. In this seminar,... More »
July 12, 2021, 2:00 pm US/Central	CPC Seminar: Hydrogen as a tracer of cosmic structures: fundamental physics and astrophysical aspects	Matteo Viel, SISSA, Trieste		Abstract: I will review the use of neutral hydrogen (HI) in the post reionization era as a tracer of the structure formation process. I will focus on atomic hydrogen both in absorption (IGM) and in emission (21cm intensity mapping). IGM is a probe of HI in volume, while intensity mapping is sensitive to the HI... More »
July 19, 2021, 2:00 pm US/Central	CPC Seminar: Topics in inflationary cosmology: reheating, gauge fields and gravitational waves	Kaloian Lozanov, UIUC		Abstract: We will review our current understanding of reheating after inflation, including various aspects of the linear and nonlinear dynamics of the inflaton field, such as parametric resonance, the generation of metric perturbations and the effects of the nonlinear evolution on the post-inflationary expansion history. We will also review the recent progress in the understanding... More »
July 26, 2021, 2:00 pm US/Central	CPC Seminar: Near-Earth Objects and High Precision Astrometry in the Solar System	Marco Micheli, NEOCC		Abstract: During the last two decades we’ve seen an increased interest, efforts and investments on the topic of Near-Earth Objects (NEOs), the consequence of an increased awareness of the danger they pose to our planet, and of the current technological capabilities to mitigate it, in case a collision can be predicted with sufficient advance notice.... More »
Aug. 9, 2021, 2:00 pm US/Central	CPC Seminar: The Importance of Being Interpretable: Toward an Understandable Machine Learning Encoder for Galaxy Cluster Cosmology	Michelle Ntampaka, Space Telescope Science Institute		Abstract: Cosmology is entering an era of data-driven science, due in part to modern machine learning techniques that enable powerful new data analysis methods. This is a shift in our scientific approach, and requires us to ask an important question: Can we trust the black box? I will present a deep machine learning (ML) approach... More »
Aug. 16, 2021, 2:00 pm US/Central	CPC Seminar: Simulating Axion Emission from a String Network with Adaptive Mesh Refinement	Joshua Foster, University of Michiga		Abstract: Axions are hypothetical particles that may explain the observed dark matter (DM) density and the non-observation of a neutron electric dipole moment. An increasing number of axion laboratory searches are underway worldwide, but these efforts are made difficult by the fact that the axion mass is largely unconstrained. If the axion is generated after... More »
Sept. 20, 2021, 2:00 pm US/Central	CPC Seminar: Asteroids as new fifth force and ultra-light dark sector tests	Youjia Wu, University of Michigan		Abstract: Radar and optical observations can provide precise measurements of the positions and velocities of asteroids. These high-precision motion data of asteroids are a great probe of fifth force with a range of solar-system size. In this talk, I will introduce how the long-range fifth force can induce precession of asteroids, and our sensitivity reaches... More »
Sept. 27, 2021, 2:00 pm US/Central	CPC Seminar: Moving Violations: Sensitive Cosmic Microwave Background Probes of Fundamental Asymmetries	Dr. Brian Keating, UCSD		Abstract: Researchers using data from the Planck satellite, a spacecraft measuring the cosmic microwave background (CMB), say they’ve recently observed a hint (at 99.2 percent confidence) of parity violation on cosmic scales. If confirmed, this result would have profound implications, not just for cosmology but for all of fundamental physics. In this lecture, Keating will... More »
Oct. 4, 2021, 2:00 pm US/Central	CPC Seminar: Torsion Balance Probes of Fundamental Physics	Eric Adelberger, University of Washington		Abstract: I will describe the main principles and challenges as well as some results of ultra-sensitive torsion-balance probes of fundamental physics performed by the University of Washington Eöt-Wash group. This group’s work was awarded the 2021 Breakthrough Prize in Fundamental Physics “for precision fundamental measurements that test our understanding of gravity, probe the nature of... More »
Oct. 25, 2021, 2:00 pm US/Central	CPC Seminar: The piezoaxionic effect	Asimina Arvanitaki, Perimeter Institute		Abstract: Axion dark matter (DM) constitutes an oscillating P- and T-violating background. Inside piezoelectric crystals, which break parity spontaneously, this axion background can result in a stress. We call this new phenomenon “the piezoaxionic effect”. When the frequency of axion DM matches the natural frequency of a bulk acoustic normal mode of the piezoelectric crystal,... More »
Nov. 1, 2021, 2:00 pm US/Central	CPC Seminar: A Novel Deep Learning Detection Method for Gravitationally Lensed Supernovae	Robert Morgan, University of Wisconsin		Abstract:The current tension on the measured value of the expansion rate of the Universe today (H0) has pushed the cosmological community to pursue more measurement techniques and larger datasets. One such technique, the characterization of systems with gravitationally lensed supernovae, is of particular interest in the Rubin Observatory era for two reasons: (1) thousands of... More »
Nov. 8, 2021, 2:00 pm US/Central	CPC Seminar: A new probe of dark energy	Vasiliki Pavlidou, University of Crete		Abstract: In the currently favored cosmological model, the energy density of the Universe is dominated by a field of unknown nature – dark energy – acting anti-gravitationally. All our current evidence for the existence of dark energy, whether in the form of a cosmological constant or an evolving field, is indirect and global (based on... More »
Nov. 15, 2021, 2:00 pm US/Central	CPC Seminar: The Smallest and Faintest Galaxies: Clues to the Nature of Dark Matter and Galaxy Formation	Burcin Mutlu-Pakdil, University of Chicago		Abstract: The smallest and faintest galaxies around the Milky Way are the most ancient, most metal-poor, and most dark-matter-dominated systems known. These extreme objects offer unique access to small scales where the stellar and dark matter content can be studied simultaneously and hold the promise of major breakthroughs in understanding the nature of dark matter,... More »
Nov. 22, 2021, 2:00 pm US/Central	CPC Seminar: Towards Precision Near-Field Cosmology	Ethan Nadler, Carnegie Observatories		Abstract: The distribution of structure on extremely small scales in the local universe is sensitive to early universe physics and dark matter particle properties. I will describe a research program aimed at reconstructing primordial density fluctuations using near-field cosmology, and particularly using the abundance of nearby ultra-faint dwarf galaxies. This includes the development of an... More »
Nov. 29, 2021, 2:00 pm US/Central	CPC Seminar: The CAMELS project	Francisco Antonio Villaescusa-Navarro, Simons Foundation		Abstract: I will present the Cosmology and Astrophysics with MachinE Learning Simulations (CAMELS) project, whose aim is to provide theoretical predictions for cosmological observables as a function of cosmology and astrophysics. Containing a set of 4,233 simulations, both N-body and state-of-the-art hydrodynamic simulations, it is designed as a large dataset to train machine learning models.... More »
Dec. 6, 2021, 2:00 pm US/Central	CPC Seminar:	Sunny Vangozzi, University of Cambridge		Abstract: Zoom: https://fermipoint.fnal.gov/service/seminars
Jan. 10, 2022, 2:00 pm US/Central	CPC Seminar: WIMP Hunting in the Black Hills: Status of the LZ Dark Matter Experiment	Sally Shaw, UCSB		Abstract: The fundamental nature of our universe is still mostly unknown: 84% of the matter in the universe is dark and qualitatively different to everything we understand via the Standard Model. Terrestrial experiments devoted to detecting interactions of dark matter particles have not yet seen a convincing signal, but we may be on the cusp... More »
Jan. 31, 2022, 2:00 pm US/Central	CPC Seminar: Kilonova Detectability with Wide-Field Instruments	Eve Chase, Los Alamos		Abstract: Kilonovae are ultraviolet, optical, and infrared transients powered by the radioactive decay of heavy elements following a neutron star merger. Observations of kilonovae, joint with gravitational wave detections, may offer strong constraints on Galactic r-process enrichment, among other astrophysical topics. Unfortunately, kilonova emission rapidly fades within days to weeks, requiring quick and efficient astronomical... More »
Feb. 7, 2022, 10:00 am US/Central	CPC Seminar: Searching for dark energy off the beaten track	Sunny Vagnozzi, University of Cambridge		Abstract: Most of the efforts in searching for dark energy (DE) have focused on its gravitational signatures, and in particular on constraining its equation of state. However, there is a lot to be learned about DE by getting off the beaten track. I will first focus on non-gravitational interactions of DE with visible matter, leading... More »
Feb. 14, 2022, 2:00 pm US/Central	CPC Seminar: SPHEREx: An All-Sky Spectral Survey	Mike Zemcov, Rochester Institute of Technology		Abstract: SPHEREx, NASA’s upcoming mid-class Explorer Mission, will perform the first all-sky spectral survey in the near infrared. Beginning in early 2025, SPHEREx will obtain 0.75-to-5μm spectra of every 6.2 arcsec pixel on the sky with spectral resolution R>35 and a 5σ sensitivity AB>19 per spectral/spatial resolution element over a two-year mission. The SPHEREx team... More »
Feb. 21, 2022, 2:00 pm US/Central	CPC Seminar: PTOLEMY: Experimental Quest to Detect Relic Neutrinos from the Big Bang	Chris Tully, Princeton		Abstract: Neutrinos produced in the early moments of the Big Bang are believed to be the second most abundant particle in the Universe. A method of experimental detection, called PTOLEMY, has been developed to map the flux of neutrinos on the sky and provide independent confirmation of the power spectrum from the inflationary pre-Big Bang... More »
Feb. 28, 2022, 2:00 pm US/Central	CPC Seminar: Cosmological interpretation of the Lyman-alpha forest	Chris Pedersen, NYU		Abstract: The Lyman-alpha forest (Lyaf) is a unique probe of structure formation on small scales. This information is particularly powerful when combined with observations of the CMB in constraints of parameters that affect the relative amplitude of small and large scales. Two prominent examples are the shape of the primordial power spectrum, and the mass... More »
March 7, 2022, 2:00 pm US/Central	CPC Seminar: Quantum field theories without infinities and naturalness	Mikhail Shaposhnikov, École Polytechnique Fédérale de Lausanne (EPFL)		Abstract: The standard way to do computations in Quantum Field Theory (QFT) is plagued by infinities and fine-tunings leading to the conception of “naturalness”, which requires the cancellation of quadratic divergences by new particles with masses right above the Fermi scale. At the same time, the ultimate outcome of any QFT (the Standard Model in... More »
March 14, 2022, 2:00 pm US/Central	CPC Seminar: The Atacama Desert’s view of the microwave sky	Erminia Calabrese, Cardiff University		Abstract: During the last two decades the Cosmic Microwave Background (CMB) has provided a unique window into the early Universe and established the Standard Cosmological Model. However, despite constraining cosmological parameters with sub-percent precision, many fundamental questions about the Universe are still unanswered and to advance the field new, more powerful CMB data are being... More »
March 21, 2022, 2:00 pm US/Central	CPC Seminar: Towards New Bubble Chamber Dark Matter Searches	Matthew Bressler, Drexel		Abstract: PICO and SBC are working towards the next bubble chamber based dark matter searches. My research focuses on prototyping and calibrations in a small PICO C3F8 bubble chamber at Drexel University, analysis of low-threshold calibration data in a small xenon bubble chamber, and construction and commissioning of a larger SBC argon bubble chamber at... More »
March 28, 2022, 2:00 pm US/Central	CPC Seminar: Observational Inference Problems in the Era of Machine Learning	Matthew Ho, Carnegie Mellon		Abstract: The fundamental problem of inference in astronomy is how to reliably measure parameters from limited observational data. Recently, machine learning approaches have shown improvement upon traditional analytical methods by learning to model high order features directly from cosmological simulations. However, these data-driven methods are highly conditional on assumptions used to generate training data and... More »
April 4, 2022, 2:00 pm US/Central	CPC Seminar: TBD	Christoph Weniger, University of Amsterdam		Abstract: TBD Zoom: https://fermipoint.fnal.gov/service/seminars
April 11, 2022, 2:00 pm US/Central	CPC Seminar: X-raying the Dark (Matter) Side with the NuSTAR Observatory	Brandon Roach, MIT	Host: Dylan Temples	Abstract: Dark matter at the keV scale has become an active topic in the last decade. The NuSTAR x-ray observatory, with its energy bandpass 3–150 keV and wide-angle aperture for unfocused x-rays, is an ideal platform to search for decaying keV-scale dark matter, e.g. sterile neutrinos. Previous NuSTAR analyses constrained much of the sterile-neutrino parameter... More »
April 18, 2022, 2:00 pm US/Central	CPC Seminar: Supermassive Black Holes from Dissipative Dark Matter	Huangyu Xiao, UWashington	Host: Dylan Temples	Abstract: Supermassive black holes at very high redshift (z>6) are difficult to explain in standard astrophysical scenarios. We study the possibility that totally dissipative self-interacting dark matter is responsible for the existence of those black holes. A series of N-body simulations for dark matter halos and Monte Carlo simulations for halo merger trees are combined... More »
April 25, 2022, 2:00 pm US/Central	Cosmological Implications from two Decades of Spectroscopic Surveys at the Apache Point observatory and Expectations for the Next Decade	Kyle Dawson, Utah	Host: Kirit Karkare	Title: Cosmological Implications from two Decades of Spectroscopic Surveys at the Apache Point observatory and Expectations for the Next Decade Abstract: The Extended Baryon Oscillation Spectroscopic Survey (eBOSS) concluded observations of the cosmic distance scale and the growth of structure in February, 2019. The three-dimensional clustering in all samples from the Sloan Digital Sky... More »
April 25, 2022, 2:00 pm US/Central	CPC Seminar: Cosmological Implications from two Decades of Spectroscopic Surveys at the Apache Point observatory and Expectations for the Next Decade	Kyle Dawson, University of Utah	Host: Kirit Karkare	Abstract: The Extended Baryon Oscillation Spectroscopic Survey (eBOSS) concluded observations of the cosmic distance scale and the growth of structure in February, 2019. The three-dimensional clustering in all samples from the Sloan Digital Sky Survey (SDSS) was used to make 15 distinct, high precision measurements of Baryon Acoustic Oscillations (BAO) to an effective redshift z<2.4... More »
May 9, 2022, 2:00 pm US/Central	CPC Seminar: Death to DAMA? Designing and assessing model independent tests of the DAMA modulation	Madeleine Zurowski, University of Melbourne	Host: Dylan Temples	Abstract: Particulate dark matter is a long hypothesised solution to various astrophysical observations seemingly at odds with a completely luminous universe. Despite the success of dark matter in explaining these observations, to date physicists have been unable to conclusively observe its interactions with Standard Model matter directly. This talk will focus on results from the... More »
May 16, 2022, 2:00 pm US/Central	CPC Seminar: Towards high-precision deep learning for dark matter searches	Christoph Weniger, University of Amsterdam, GRAPPA	Host: Anastasia Sokolenko	Abstract: Observational data relevant for astroparticle physics and astrophysical searches for dark matter becomes increasingly complex and detailed. We are in a situation where often what we can learn from new observations is limited not by the amount of data, but by the sophistication of our analysis tools and the quality and detail of our... More »
June 6, 2022, 2:00 pm US/Central	CPC Seminar: Ruling out QCD Phase Transition as a PBH Origin of LIGO/Virgo Events	Joaquim Iguaz, Laboratoire d'Annecy-le-Vieux de Physique Théorique	Host: Dylan Temples	Abstract: The best-motivated scenario for a sizable primordial black hole (PBH) contribution to the LIGO/Virgo binary black hole mergers invokes the QCD phase transition, which naturally enhances the probability to form PBH with masses of stellar scale. We reconsider the expected mass function associated not only to the QCD phase transition proper, but also the... More »
June 13, 2022, 2:00 pm US/Central	CPC Seminar: Precision Cosmology with CMB and 21cm	Zhilei Xu, MIT	Host: Dylan Temples	Abstract: Over the past decades, observations of the cosmic microwave background (CMB) have established the standard cosmological model. In the future, 21cm signals from neutral hydrogen have great potential for cosmological and astrophysical studies. In this talk, I will review the previous CMB observations and how it established the ΛCDM cosmology model. Then I will... More »
Sept. 12, 2022, 2:00 pm US/Central	CPC Seminar: First results of the LZ dark matter experiment and the impact of accidental coincidence backgrounds	Kelly Stifter, Fermilab	Host: Dylan Temples	Abstract: The LUX-ZEPLIN (LZ) experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. Results from LZ’s first search for Weakly Interacting Massive Particles (WIMPs) showed the data to be consistent with a background-only hypothesis, setting new limits on... More »
Oct. 3, 2022, 2:00 pm US/Central	CPC Seminar: High Voltage Electrode Backgrounds in the Context of S2-only Analyses in Dual-Phase Xenon TPCs	Ryan Linehan, Fermilab	Host: Dylan Temples	Abstract: Approximately 15% of the matter density in the universe is composed of Standard Model particles, while the other 85% is composed of an enigmatic “dark” matter whose fundamental properties are unknown. In recent decades, there has been substantial interest in performing a direct detection of dark matter scatters on Standard Model particles, but currently... More »
Oct. 10, 2022, 2:00 pm US/Central	CPC seminar: Looking for dark matter in gamma rays - can machine learning help?	Gabrijela Zaharijas, U. Nova Gorica	Host: Elena Pinetti	Abstract: We live in a ‘golden’ time for studies of high-energy (HE) astrophysics as a series of satellite and ground based telescopes currently provide high-precision data. Multi-messenger and -wavelength analysis of these rich data sets are critical to answer the century old questions on the origin of cosmic rays and physics at the heart of most energetic accelerators in the Universe. This progress... More »
Oct. 17, 2022, 2:30 pm US/Central	CPC Seminar: Floating Dark Matter in Celestial Bodies	Rebecca Leane, SLAC	Host: Elena Pinetti	Note the change of time and location: 2.30pm in PPD/ West Wing-WH10NW – Wilson Hall 10th fl North West Abstract: Dark matter can be captured in stars and planets after scattering and losing sufficient energy to become gravitationally bound. I will discuss a new framework to describe what happens when dark matter is captured by these objects, and demonstrate the... More »
Oct. 24, 2022, 2:00 pm US/Central	CPC Seminar: TBD -- Rescheduled	Martina Gerbino, INFN	Host: Kirit Karkare	This seminar will be rescheduled to a future date. Thank you for understanding. Abstract: TBD Zoom: https://fermipoint.fnal.gov/service/seminars
Oct. 31, 2022, 2:00 pm US/Central	CPC Seminar: The DAMIC-M Experiment: Status and First Results	Danielle Norcini, University of Chicago	Host: Dylan Temples	Abstract: The DAMIC-M experiment uses skipper charge-coupled devices (CCDs) to search for dark matter underground at the Laboratoire Souterrain de Modane. The kg-scale detector is designed to resolve single electron recoils from low-mass WIMP and hidden photon scatters on silicon. We will discuss the status of DAMIC-M, recent calibration studies, and the first search for... More »
Nov. 7, 2022, 2:00 pm US/Central	CPC Seminar: Dark matter freeze-in produces large post-inflationary isocurvature	Kim Berghaus, Stonybrook	Host: Dylan Temples	Abstract: In this talk I will show that the nonthermal nature of dark matter freeze-in production leads to large, totally correlated dark matter-photon isocurvature perturbations, which are imprinted in anisotropies of the cosmic microwave background (CMB). Isocurvature is typically expected from inflationary physics but the isocurvature from freeze-in arises post inflation. Using millicharged dark matter... More »
Nov. 14, 2022, 2:00 pm US/Central	CPC Seminar: Freezing in a hot bath	Saniya Heeba, McGill University	Host: Dylan Temples	Abstract: In the absence of a clear dark matter signal, models beyond WIMPs have recently gained a lot of traction. One of the leading alternatives is the Feebly Interacting Massive Particle (FIMP) paradigm, where the dark matter abundance is set by the leakage of energy from the visible sector by the so-called freeze-in mechanism. Relic density... More »
Nov. 21, 2022, 2:00 pm US/Central	CPC Seminar - Black Holes from the Early Universe	Valerio De Luca, University of Pennsylvania	Host: Elena Pinetti	Abstract: Primordial black holes are a fascinating candidate for the dark matter in the universe. We discuss about their formation and evolution across the cosmic history, and focus on their detectability at gravitational wave experiments. Zoom: https://fermipoint.fnal.gov/service/seminars
Nov. 28, 2022, 2:00 pm US/Central	CPC Seminar: Sub-GeV direct detection with Quantum Dots and Molecules	Carlos Blanco, Princeton Unviersity	Host: Dylan Temples	Abstract: As the WIMP draws under increasing tension thanks to the ever-increasing sensitivity of direct detection experiments, the majority of DM parameter space outside of the weak scale remains to be explored. Sub-GeV DM can excite electronic transitions in a variety of molecular and nano-scale systems which have sub-eV scale thresholds. Furthermore, non-adiabatic couplings may... More »
Dec. 5, 2022, 2:00 pm US/Central	CPC Seminar - TBD	Hongwan Liu, New York University	Host: Elena Pinetti	Abstract: TBD Zoom: https://fermipoint.fnal.gov/service/seminars
Jan. 9, 2023, 2:00 pm US/Central	Searching for Dark Matter with BREAD: Broadband Reflector Experiment for Axion Detection - CPC Seminar			BREAD is a novel dish antenna for broadband ~µeV-eV range axion and wave-dark matter detection, which allows to utilize state-of-the-art high-field solenoidal magnets. At these masses it is difficult to scale up traditional resonant detectors to the required volume. However, at metallic surfaces in a high magnetic field dark matter axions can convert to photons... More »
Jan. 23, 2023, 2:00 pm US/Central	CPC Seminar: Utilizing Shape Information in Statistical Analysis for Mu2e	Cole Kampa, Northwestern University	Host: Dylan Temples	Abstract: Mu2e, the muon-to-electron conversion experiment, will search for Charged Lepton Flavor Violation (CLFV), which is forbidden in the Standard Model (SM) of particle physics. The experiment is based at Fermilab and is currently in the construction phase. I will briefly describe the experimental philosophy and methods of Mu2e, as well as provide a summary... More »
Jan. 29, 2023, 2:00 pm US/Central	CPC Seminar: Something new in the gamma-ray sky	Damiano Caprioli, University of Chicago	Host: Elena Pinetti	In the past few years new classes of gamma-ray emitters have been discovered, unlocking unprecedented views on cosmic ray sources and on the mechanisms responsible for particle acceleration and propagation. In this talk I outline several such examples: 1) TeV haloes around supernova remnants, pulsar wind nebulae, and star clusters; 2) GeV-TeV emission from the... More »
Feb. 6, 2023, 2:00 pm US/Central	CPC Seminar: Particle Astrophysics with the TeV Sun	Mehr Un Nisa, Michigan State University	Host: Elena Pinetti	Abstract: The propagation of cosmic rays (CRs) in the solar system is subject to the influence of Sun’s magnetic fields. The local CR flux is not only modulated by the Sun, but also undergoes complex interactions in the photosphere. Studying the flux of secondary photons and neutrinos produced in CR interactions with the Sun offers... More »
Feb. 13, 2023, 2:00 pm US/Central	CPC Seminar: The Dark Energy Spectroscopic Instrument: Project Updates	Julien Guy, LBNL	Host: Dylan Temples	Abstract: The Dark Energy Spectroscopic Instrument (DESI) is undertaking a 5-year spectroscopic survey of 40 million galaxies and quasars measured over a 14,000 square degree footprint. 30 percent of the dark time survey was completed by the end of October 2022. The analysis of the survey validation data has demonstrated that the survey is on... More »
Feb. 20, 2023, 2:00 pm US/Central	QCD axion dark matter with a small decay constant	Keisuke Harigaya, University of Chicago	Huangyu Xiao	The QCD axion explains why QCD almost preserves the charge-conjugation parity symmetry. The QCD axion is also a dark matter candidate and is under intensive experimental searches for a wide range of its decay constant. In this talk, I will review the production mechanisms of axion dark matter in the early universe, focusing on those... More »
Feb. 27, 2023, 2:00 pm US/Central	CPC Seminar: Observing sub-nHz gravitational waves with pulsar parameter drift	William DeRocco, UC Santa Cruz	Host: Elena Pinetti	Abstract: Gravitational waves with frequencies below 1 nHz are notoriously difficult to detect. With periods exceeding current experimental lifetimes, they induce slow drifts in observables rather than periodic correlations. Observables with well-known intrinsic contributions provide a means to probe this regime. In this talk, I will demonstrate the viability of using observed pulsar timing parameters... More »
March 13, 2023, 2:00 pm US/Central	Precision Metrology with Photons, Phonons and Spins: Answering Major Unsolved Problems in Physics and Advancing Translational Science	Michael Tobar, University of West Australia	Elena Pinetti	The Quantum Technologies and Dark Matter research laboratory has a rich history of developing precision tools, including the development and application of novel low-loss and highly sensitive resonant photonic and phononic cavities, such as whispering gallery and re-entrant cavities, as well as photonic band gap and bulk acoustic wave structures. These cavities have been used... More »
May 1, 2023, 2:00 pm US/Central	CPC Seminar: Hydrodynamical simulations of the first stars in the cold and fuzzy dark matter cosmologies	Mihir Kulkarni, University of Toledo	Host: Dylan Temples	Abstract: In the standard model of cosmology with cold dark matter (CDM), the first stars are expected to form in dark matter minihalos of mass 10^5-10^7 Msun. The formation of the first stars can be delayed depending on the feedback processes and environment. We provide a fit for the minimum dark matter halo mass required... More »
May 8, 2023, 2:00 pm US/Central	CPC Seminar: Seeing the invisible: the search for low-mass axion dark matter	Chiara Salemi, Stanford	Host: Dylan Temples	Abstract: Multiple astrophysical and cosmological observations have shown that the visible matter described by the Standard Model is only a small fraction of the energy in the universe. We believe that there is about five times as much dark matter, which is likely comprised of massive particles that interact very little or not at all... More »
May 15, 2023, 2:00 pm US/Central	CPC Seminar: Adventures in processing precursor LSST data	Huan Lin, Fermilab	Host: Elena Pinetti	Abstract: The Legacy Survey of Space and Time (LSST) is an ambitious optical imaging survey, to be undertaken at the Vera C. Rubin Observatory in Chile, using an 8.4-meter telescope and 3.2-gigapixel camera that will observe 18,000 deg^2 of sky over 10 years, generating a final 15-petabyte database cataloging 20 billion galaxies and 17 billion... More »
June 5, 2023, 2:00 pm US/Central	Axions in High-Energy Astrophysical Plasmas	Anirudh Prabhu, Princeton University	Huangyu Xiao	Axions are a well-motivated extension to the Standard Model and are among the best candidates to explain dark matter. Their detection is made difficult by the fact that they couple very weakly to particles in the Standard Model. High-energy astrophysical settings host extreme conditions wherein axions may be produced in great abundance. In this talk,... More »
July 10, 2023, 2:00 pm US/Central	CPC Seminar: The NEWS-G light Dark Matter search experiment: Calibration techniques and physics results from a 10 day exposure with pure methane gas	Daniel Durnford, University of Alberta	Host: Dylan Temples	Abstract: The NEWS-G direct detection dark matter search experiment uses spherical proportional counters (SPCs) with light noble gasses to search for low mass WIMP-like dark matter. The current iteration of the experiment consists of a large 140 cm diameter SPC installed at SNOLAB – benefiting from a new sensor design, improvements in detector performance, and... More »
July 17, 2023, 2:00 pm US/Central	CPC Seminar: Forward modeling of galaxy cluster optical systematics	Ben Zhang, U. Chicago	Host: Dylan Temples	Abstract: Galaxy cluster abundance is one of the pillars of modern cosmology, with weak-lensing the gold standard for cluster mass calibration. Despite this achievement in modern cosmology, uncertainties and systematics in cluster observables hampers this probe in cosmological studies. With the aim of achieving percent-level cluster mass estimation, I present the modeling of two systematics... More »
Sept. 11, 2023, 2:00 pm US/Central	CPC Seminar: Probing Dark Matter Substructures with Fast Radio Bursts	Huangyu Xiao, Fermilab		The matter power spectrum is weakly constrained on subgalactic scales while physics beyond the Lambda CDM paradigm can leave unique imprints on small scales, such as an early matter-dominated epoch, and isocurvature fluctuations induced by post-inflationary axions. We propose measuring the Shapiro time delays of Fast Radio Bursts (FRBs) along two sightlines as a new... More »
Sept. 18, 2023, 2:00 pm US/Central	CPC Seminar: Count Intensity Interferometry and the Angular Resolution Frontier	Albert Stebbins, Fermilab	Host: Dylan Temples
Sept. 25, 2023, 2:00 pm US/Central	CPC Seminar: Seeing highly anisotropic gravitational wave backgrounds from phase transitions	Arushi Bodas, Fermilab	Host: Dylan Temples	Abstract: A stochastic gravitational wave background (GWB) produced from a first-order phase transition in the early universe would necessarily exhibit anisotropies analogous to the CMB. In multi-field inflationary scenarios, however, anisotropies in GWB could differ significantly from those of the CMB if sourced by a quantum field different from the one sourcing CMB. In these... More »
Oct. 2, 2023, 2:00 pm US/Central	CPC Seminar: TBD	Nathan Saffold, Fermilab	Host: Dylan Temples
Nov. 6, 2023, 2:00 pm US/Central	Supermassive primordial black holes from inflation	Aurora Ireland, University of Chicago	Host: Huangyu Xiao	Much remains to be understood about the origin and evolution of our universe’s largest supermassive black holes (SMBHs). In this talk, I motivate the possibility that some fraction of these SMBHs may be primordial in origin, having formed from the direct collapse of density perturbations seeded by inflation. Such a scenario is naively in conflict... More »
Nov. 13, 2023, 2:00 pm US/Central	CPC Seminar: TBD	Gordan Krnjaic, Fermilab	Host: Huangyu Xiao	TBD
Nov. 20, 2023, 2:00 pm US/Central	CPC Seminar: Constraining primordial non-Gaussianity using the large-scale modulation of small-scale statistics	Utkarsh Giri, U Wisconsin, Madison	Host: Dylan Temples	Abstract: Searching for signatures of non-Gaussianity in primordial fluctuations is one of the foremost quests in modern cosmology. A successful detection will rule out single-field inflation models. In my talk, I will present a novel, non-perturbative formalism to constrain the local type primordial non-Gaussianity (PNG) parameter f_NL, tapping into information from deeply non-linear scales. We... More »
Nov. 27, 2023, 2:00 pm US/Central	Constraints on Long-Range Interactions Between Dark Matter and the Standard Model	Zachary Bogorad, Stanford University	Host: Huangyu Xiao	There are a variety of experimental and astrophysical constraints on non-gravitational interactions of dark matter with the Standard Model, but most assume that such interactions are short-ranged, with individual dark matter particles interacting with individual Standard Model particles. It is also possible, however, for dark matter to have weak but long-ranged interactions with the Standard... More »
Dec. 4, 2023, 2:00 pm US/Central	CPC Seminar: Probing primordial non-Gaussianity by reconstructing the initial conditions with machine learning	Xinyi Chen, Yale University	Host: Dylan Temples	Abstract: Inflation remains one of the enigmas in fundamental physics. While it is difficult to distinguish different inflation models, information contained in primordial non-Gaussianity (PNG) offers a route to break the degeneracy. In galaxy surveys, the local type PNG is usually probed by measuring the scale-dependent bias in the galaxy power spectrum on large scales,... More »
Dec. 11, 2023, 2:00 pm US/Central	CPC Seminar: TBD	Adam Miller, Northwestern University	Host: Dylan Temples	Abstract: TBD
Jan. 8, 2024, 2:00 pm US/Central	CPC Seminar: Blue Isocurvature Perturbations and EFTofLSS based Forecasts	Sai Chaitanya Tadepalli, U Wisconsin, Madison	Host: Dylan Temples	Abstract: In this talk, we will present axionic blue-tilted isocurvature power spectra and its possible constraints/sensitivities from experiments. Firstly, we will discuss the strongly blue tilted (nI~4) isocurvature spectrum generated during inflation for the mass parameter region just when the quantum oscillator modes are starting to be underdamped. Interestingly, there exist parametric regions with a... More »
Jan. 22, 2024, 2:00 pm US/Central	CPC Seminar: Stress as a Background in Light Dark Matter Experiments and as a Decoherence Mechanism in Superconducting Qubits	Roger Romani, U.C. Berkeley	Host: Dylan Temples	Abstract: Dark matter direct detection experiments using cryogenic calorimeters see unexplained bursts of energy in their phonon and sensor systems at low energies, a background often called the Low Energy Excess (LEE). Simultaneously, superconducting quantum bits decohere at much higher than expected rates due to unexplained bursts of quasiparticles in their superconductors. Combined with the... More »
Jan. 29, 2024, 2:00 pm US/Central	CPC seminar: Probing Dark Matter Energy Injection in the Cosmic Dawn with the 21-cm Power Spectrum	Yitian Sun, MIT	Elena Pinetti	The 21-cm signal provides a novel avenue to measure the thermal state of the universe during cosmic dawn and reionization, and thus a probe of exotic energy injection such as those from decaying or annihilating dark matter (DM). These DM processes are inherently inhomogeneous: both decay and annihilation are density dependent, and furthermore the fraction... More »
Feb. 5, 2024, 2:00 pm US/Central	CPC Seminar: Scatterings of dark matter and relic neutrinos off cosmic rays near supermassive black holes	Gonzalo Herrera Moreno, Virginia Tech	Host: Elena Pinetti	Abstract: Some supermassive black holes at the center of galaxies may accelerate cosmic rays to very high energies, producing high-energy neutrinos and gamma-rays observable on Earth. The dark matter in the vicinity of supermassive black holes may scatter off protons, electrons, neutrinos and photons, perhaps cooling them too fast. Furthermore, a fraction of the dark... More »
Feb. 26, 2024, 2:00 pm US/Central	CPC Seminar: Direct Detection of Dark Matter using Quantum Sensors and Techniques	Karthik Ramanathan, California Institute of Technology	Host: Dylan Temples	Abstract: Determining the nature of dark matter (DM), a mysterious ‘missing mass’ in the universe, is crucial to completing our models of cosmology and high-energy physics. Two recent areas of experimental interest, among the many decades of potential DM masses, are particle-like ‘light DM’ with masses less than a GeV and wave-like candidates of O(10) ueV. In this talk, I will... More »
March 4, 2024, 2:00 pm US/Central	CPC Seminar: Expanding the mass range for axion searches with HAYSTAC	Xiran Bai, Yale University	Host: Dylan Temples	Abstract: The axion is a well-motivated hypothetical particle originally proposed to solve the Strong CP problem in quantum chromodynamics (QCD), and sufficiently light axion may also be a dark matter candidate. The Haloscope At Yale Sensitive To Axion CDM (HAYSTAC) Experiment is actively searching for axion dark matter using a resonant microwave cavity and quantum... More »
March 11, 2024, 2:00 pm US/Central	CPC Seminar: Primordial Black Holes and the Era of Gravitational Cosmology	Antonio Riotto, University of Geneva	Host: Elena Pinetti	The discovery of a gravitational wave signal coming from the merger of two black holes by the LIGO/Virgo collaboration has initiated the new era of gravitational wave astronomy. Primordial black holes were immediately suggested to be responsible for such a signal thus initiating a flourish research activity on the subject on which we will report... More »
March 18, 2024, 2:00 pm US/Central	CPC Seminar: Quantum-Noise-Limited Parametric Amplifiers: From Theory to Application	Nikita Klimovich, University of Oxford	Host: Dylan Temples	Abstract: Superconducting traveling wave parametric amplifier (TWPA) development has progressed considerably in the past few years driven by the needs for broadband, quantum-noise-limited amplification in the fields of quantum computing, dark matter, and astrophysics. In this talk, I will provide a general background to the theory and operation of TWPAs, demonstration of quantum limited noise... More »
March 25, 2024, 2:00 pm US/Central	CPC Seminar: Is Dark Matter hiding in plain sight? In search for Dark Matter among gamma-ray sources	Aurelio Amerio, IFIC, University of Valencia	Host: Elena Pinetti	Abstract: Among the gamma-ray sources identified through the Fermi Large Area Telescope, approximately one-third of them currently defies a clear association with any specific class of astrophysical sources. We will study their energy spectrum distribution – one of the most promising features to unveil the origin of these puzzling gamma-ray sources. We will introduce... More »
April 1, 2024, 2:00 am US/Central	Probing exotic energy injection with the CMB and early star formation	Wenzer Qin, MIT		Dark matter interactions with Standard Model particles can inject energy at early times, altering the standard evolution of the early universe. In particular, this energy injection can perturb the spectrum of the cosmic microwave background (CMB) away from that of a perfect blackbody, alter the CMB anisotropy spectrum, and affect processes by which the first... More »
April 15, 2024, 2:00 pm US/Central	CPC Seminar: Axion Dark Matter	Pierre Sikivie, University of Florida	Host: Dylan Temples	Abstract: Axions have a double motivation: they solve the “strong CP problem” of the Standard Model of elementary particles and they are a candidate for the dark matter of the Universe. Dark matter axions can be detected on Earth by converting them to photons in an electromagnetic cavity permeated by a strong magnetic field. A... More »
April 22, 2024, 2:00 pm US/Central	CPC Seminar: TBD	Jialin Yu, Illinois Institute of Technology	Host: Dylan Temples	Abstract: TBD
April 29, 2024, 2:00 pm US/Central	CPC Seminar: Sunyaev-Zeldovich Science with the South Pole Telescope and Future Cosmic Microwave Background Surveys	Srinivasan Raghunathan, University of Illinois Urbana-Champaign	Joshua Sobrin (Host)	Secondary anisotropies of the cosmic microwave background (CMB) are known to be remarkable probes of astrophysics and cosmology. The properties of free streaming CMB photons from the surface of last scattering are altered by their interaction with matter in the Universe carrying crucial information about the the Epoch of Reionisation (EoR) and also the origin,... More »	Speaker Webpage
May 6, 2024, 2:00 am US/Central	Millicharged Cosmology	Xucheng Gan, New York University		In the standard model, the minimal electric charge an elementary particle can have is 1/3. This raises a fundamental question: Do particles with smaller charges exist? Termed as the ‘millicharged particle’ (mCP), this new type of particle is divided into two categories: the Pure mCP and the mCP resulting from the kinetic mixing. Even though... More »
May 13, 2024, 2:00 pm US/Central	CPC Seminar: Studying the Efficacy of Superconducting Qubits as Low-threshold Particle Detectors	Ryan Linehan, Fermilab	Host: Dylan Temples	Abstract: In recent years, the lack of a conclusive detection of WIMP dark matter at the 10 GeV/c^2 mass scale and above has encouraged development of low-threshold detector technology aimed at probing lighter dark matter candidates. Detectors based on Cooper-pair-breaking sensors have emerged as a promising avenue for this detection due to the low (meV-scale)... More »
July 15, 2024, 2:00 pm US/Central	Primordial Features of Isocurvature: the Axion Case and Beyond	Lingfeng Li, Brown University	host: Huangyu Xiao	If a sector other than inflaton survives in the late universe, its quantum fluctuation generically brings isocurvature modes. The typical case is the complex scalar with spontaneous symmetry breaking, with the remaining U(1) global symmetry and the associated massless goldstone boson. The goldstone mode can be recognized as the QCD axion or axion-like particle (ALP)... More »
July 22, 2024, 2:00 pm US/Central	CPC Seminar: New constraints on the central mass contents of Omega Centauri from combined stellar kinematics and pulsar timing	Andrès Banares Hernandez, IAC	Host: Elena Pinetti	Abstract: We perform a combined analysis of stellar kinematics and line-of-sight accelerations of millisecond pulsars to investigate the mass contents of Omega Centauri. We consider multiple mass components, such as stellar remnants, an intermediate-mass black hole, and dark matter. By self-consistently incorporating multiple independent datasets, we obtain stringent constraints on these mass distributions. Our... More »
July 29, 2024, 2:00 pm US/Central	Fireball Anti-Nucleosynthesis	Erwin H. Tanin, Stanford University		The baryon sector of the present universe is almost entirely made of matter. High-energy collisions of cosmic rays with particles of the interstellar medium can produce small amounts of anti-nucleons, which may, in turn, form even smaller amounts of anti-nuclei through rare coalescences. Given the expectation of extremely scarce astrophysical anti-nuclei, a robust detection of... More »
Aug. 12, 2024, 2:00 pm US/Central	CPC Seminar: MADMAX - Design and First Results	David Leppla-Weber, Deutsches Elektronen-Synchrotron (DESY)	Joshua Sobrin (Host)	Axions are a popular dark matter candidate. They would not only solve the mystery behind dark matter but their existence could also explain the absence of CP violating effects in quantum chromodynamics. The Magnetized Disk and Mirror Axion eXperiment (MADMAX) is designed to search for axions around a mass of 100 μeV. It uses a... More »
Sept. 9, 2024, 2:00 pm US/Central	CPC Seminar: Levitated optomechanical sensors for dark matter and sterile neutrino searches	Yu-Han Tseng, Yale University	Joshua Sobrin (Host)	Recent advances in levitated optomechanics have enabled the detection of tiny forces through precise control of microscopic objects in vacuum. These technologies present new experimental platforms to probe weakly coupled phenomena in particle and nuclear physics. I will describe a dark matter search based on optically trapped, femtogram-scale silica nanospheres. In ultra-high vacuum, the sensitivity... More »
Sept. 16, 2024, 2:00 am US/Central	Atom interferometry probes of dark matter	Yufeng Du, Caltech		Atom interferometry experiments have unique advantages in searching for various kinds of dark matter (DM). In this talk, I will introduce effects in such experiments from light DM scattering and from gravitational field of a macroscopic DM. First we discuss sensitivities of matter wave interferometers to a light DM subcomponent at sub-GeV masses through decoherence... More »
Sept. 23, 2024, 2:00 am US/Central	Black holes whenever	Zachary Picker, University of California, Los Angeles		Black holes are (re)emerging into one of the most exciting dark matter candidates. I will attempt a holistic overview of this niche of the astroparticle world, looking at observations, constraints, exotic phenomenology, and perhaps most importantly, their formation. It turns out that there is a surprisingly rich variety of formation mechanisms for primordial black holes—in... More »
Sept. 30, 2024, 2:00 am US/Central	Gamma rays from supernova axions converting in stellar magnetic fields	Yujin Park, University of California, Berkeley		Proto-neutron stars, formed in the center of Type-II supernovae, represent promising science targets for probing axions. The hypothetical particles are emitted via e.g. the Primakoff process and can modify the cooling rate of the proto-neutron stars and also convert to observable gamma rays while propagating through astrophysical magnetic field. Observations of Supernova 1987 (SN 1987A)... More »
Oct. 7, 2024, 2:00 am US/Central	New Challenges and New Tools for CMB Experiments	Cynthia Trendafilova, University of Illinois Urbana-Champaign		Current and next-generation Cosmic Microwave Background (CMB) surveys will measure the anisotropies of the CMB with unprecedented precision. Complementary to other laboratory and astrophysical searches, these measurements provide a probe to search for physics beyond the Standard Model. In this talk, I will discuss some applications of this data to search for signatures of dark... More »
Oct. 14, 2024, 2:00 pm US/Central	CPC Seminar: Photon Counting Interferometry to Detect Geontropic Space-Time Fluctuations with GQuEST	Sander Vermeulen, Caltech	Joshua Sobrin (Host)	New approaches to finding a theory of quantum gravity, based on the holographic principle, consistently predict the existence of quantum fluctuations of space-time. The GQuEST experiment uses a new experimental technique, called ‘photon counting interferometry’, that allows laser interferometers to measure individual photons that have been produced by the space-time fluctuation signal, while disregarding noise... More »
Oct. 21, 2024, 2:00 pm US/Central	CPC Seminar: The Simons Observatory: Pre-deployment Optical Characterization and Current Status	Katie Harrington, Argonne National Laboratory (ANL)	Joshua Sobrin (Host)	The Simons Observatory (SO) is a next generation Cosmic Microwave Background (CMB) experiment that is currently undergoing commissioning in the Chilean Atacama Desert. SO’s scientific objectives encompass the characterization of the primordial perturbations, the measurement of the number of relativistic species and the sum of the mass of neutrinos, improving our understanding of galaxy evolution,... More »
Oct. 28, 2024, 2:00 pm US/Central	Probing Long-Range Force Between Neutrinos from Cosmic Structures	Xuheng Luo, Johns Hopkins University		The long-range force between neutrinos is poorly constrained. In the late-time universe, a long-range force that is a few orders of magnitude stronger than gravity can induce Jeans perturbation instability in the cosmic neutrino background, drastically changing its large-scale behavior. In this talk, I will describe how the cosmic neutrino background evolves and forms nonlinear... More »
Nov. 4, 2024, 2:00 am US/Central	CPC Seminar: TBD	Oren Slone, Stony Brook University		TBD
Nov. 11, 2024, 2:00 pm US/Central	CPC Seminar: Cosmology from the DESI Data Release 1	Otávio Alves, University of Michigan	Joshua Sobrin (Host)	On April 4th, 2024, the Dark Energy Spectroscopic Instrument (DESI) released its first set of cosmological results based on measurements of the baryon acoustic oscillations (BAO) scale in the spatial distribution of galaxies and quasars, and in the Lyman-alpha forest. Those measurements constrain the expansion history of the Universe in the redshift range 0.1 <... More »	Speaker Webpage
Nov. 18, 2024, 2:00 pm US/Central	Testing the kinematics and dynamics of inflation using μ-distortion anisotropies	David Zegeye, University of Chicago		Cosmic inflation is the most compelling model for the earliest moments of our Universe and provides a mechanism for seeding the initial density perturbations of cosmological observables. Modeled as a single scalar field known as the inflaton, observations can probe physics up to ~ 10^{14} GeV, far beyond the reach of any terrestrial experiment. Measuring... More »