Abstract:
Sub-GeV dark matter is a well-motivated possibility. However, its feeble interactions make it hard to detect, often falling below experimental thresholds, requiring new detection ideas. In this talk I will describe two complementary, data-driven strategies to close in on light dark matter. First, I will show how large neutrino observatories can be repurposed to look for the cumulative imprint of many tiny dark-matter interactions, identified through a distinctive yearly variation expected from Earth’s motion. Second, I will present a new astrophysical approach that uses faint hydrogen emission from nearby, quiescent dwarf galaxies as a tracer of energy injected by dark matter, and demonstrate how existing observations already yield powerful new constraints. Together these methods leverage current instruments in new ways and outline clear paths to substantially improved dark matter sensitivity in the near term.