Theory Seminar (High Energy/Cosmology) |
Events on Thursday, September 8th, 2022
- Axion Solar Halos
- Time: 12:00 pm
- Place: Chamberlin 5280
- Speaker: Joshua Eby, Tokyo U., IPMU
- Abstract: Ultralight dark matter (ULDM) is known to form self-gravitating bound states through gravitational relaxation. There are intriguing hints in the literature suggesting similar dynamics might lead to overdensities in the solar system as well, with ULDM becoming bound to the Sun. These Solar Halos can be probed by experiments on Earth when their radius R > 1 AU, which implies ULDM particle masses m < 10^{-14} eV. For larger masses m, space-based missions on orbits within 1 AU can probe small, compact Solar Halos with exceptional reach; for scalar couplings probable in current and near-future atomic clock systems, the sensitivity can exceed that of Equivalence Principle tests and probe well-motivated space for natural scalar field models. I will review the state of the art on these topics, including the use of asteroids as direct probes of DM density, as well as several exciting NASA and international missions that motivate searches aboard space probes.