Graduate student Jatan Buch, postdocs Manuel Buen-Abad and John (Shing-Chau) Leung, and Prof. Fan study the mutual relationship between dark matter-electron scattering experiments and possible new dark matter substructure nearby hinted by the data from Gaia satellite. In particular, they show how future data could probe and constrain the fraction of dark matter in substructure, even when it constitutes a subdominant component of the local dark matter density.
Motivated by a possible excess in the low-energy electronic recoil data reported by XENON1T collaboration, Graduate student Jatan Buch, postdocs Manuel Buen-Abad and John (Shing-Chau) Leung, and Prof. Fan explore the exotic possibility that dark matter decays or annihilations taking place in our galaxy may produce a flux of relativistic very weakly-coupled bosons, axions or dark photons. They show that there exist several generic upper bounds for this flux on Earth assuming generic minimal requirements for DM, which will survive even if XENON1T excess doesn’t stay.