Dan Hooper, University of Chicago

"Black Holes in the Early Universe"

Abstract: Any abundance of black holes that was present in the early universe will evolve as matter, making up an increasingly large fraction of the total energy density as space expands. This motivates us to consider scenarios in which the early universe included an era that was dominated by low-mass (M < 10^9 g) black holes, which evaporate prior to primordial nucleosynthesis. Within this context, Hawking radiation can provide an attractive mechanism for the production of dark radiation and dark matter. I will also discuss the mergers of black holes in the early universe, which could lead to a potentially detectable background of hot (~eV-keV) gravitons, and a stochastic background of high-frequency gravitational waves. I will also comment on the role that primordial black holes may have played in the process of baryogenesis.