CPC Seminar: Probing cosmology using dark matter microhalos

  • Nov. 2, 2020, 2:00 pm US/Central
  • 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 their usage as cosmological probes. A theoretical understanding of the microhalo-cosmology connection demands numerical simulation, but microhalos are too small and dense to simulate up to the present day in full cosmological context. One way to meet this challenge is to use controlled numerical simulations to develop (semi)analytic models of dark matter structure. I will discuss several such models, which describe the formation of the first halos and their subsequent evolution as they accrete onto larger systems. I will also explore applications of these models, including probing inflation’s late stages via the small-scale primordial power spectrum and breaking a degeneracy between the properties of thermal-relic dark matter and the postinflationary history.

For more information, please contact Yu-Dai Tsai at ytsaiATfnal.gov.