Detecting ultra light primordial black holes as the dark matter candidate

Speaker: Ranjan Laha (IISc, Bangalore)

Date/Time: 12th February 2021 (Friday) 2:30 PM IST

Abstract:

Primordial black holes (PBHs) are a well-motivated candidate of dark matter (DM). There exists a wide range of PBH masses where it can comprise of the full DM density. In this talk, I will concentrate on the ultra-light range of PBH DM (mass of PBH $\lesssim$ 10$^{17}$ g). These ultra-light PBHs can be discovered or constrained via their Hawking radiation. We use the observations of the 511 keV gamma-ray line and MeV gamma-ray observations at the Galactic Center to show that PBHs with masses less then 1.2 $\times$ 10$^{17}$ g cannot comprise all of the DM, setting the strongest bound on ultra-light PBHs. I will also briefly discuss how a near future MeV gamma-ray telescope, like AMEGO, can discover PBHs in the mass range where it can make up 100% of the DM density.