Searching for sub-GeV dark matter with celestial objects - Javier Acevedo (SLAC)

Abstract: While sub-GeV dark matter (DM) is a well-motivated possibility, its detection in the lab remains challenging. Celestial objects can serve as a complementary probe in this range, as they can capture large amounts of DM that give rise to detectable signals. In this talk, I will first explore the sensitivity of inner Galaxy white dwarfs to DM annihilation into long-lived mediators, producing gamma-rays. Using Fermi and H.E.S.S. data alongside various DM halo profiles, I will show how the resulting sensitivity lies multiple orders of magnitude beyond what current experiments can achieve in the sub-GeV range. Additionally, I will discuss the potential for detecting light DM in other celestial objects if long-range interactions exist in the dark sector. Such forces would lower the evaporation mass threshold for which DM particles are retained in a celestial body, thereby expanding searches to a much wider range than previously thought.