- Feb. 7, 2022, 10:00 am US/Central
- 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 to the possibility of “direct detection of dark energy” (analogous to direct detection of dark matter): I will argue that such interactions can and potentially may already have been detected in experiments such as XENON1T, while discussing some of their complementary cosmological and astrophysical signatures. I will then discuss early- and late-time consistency tests of LCDM, and how these may shed light on (early and late) DE, particularly in relation to the Hubble tension. I will present two such tests based on the early ISW effect and the ages of the oldest astrophysical objects in the Universe. If time allows, I will turn to more general ultralight particles (which may have to do with either dark matter or DE) and discuss new ways of probing these, using black hole shadows and planetary objects such as asteroids.