Particle Theory Seminar | Gordan Krnjaic (Fermilab and Chicago U., EFI and Chicago U., KICP) – Primordial Black Hole Domination: Dark Matter, Dark Radiation, and Gravitational Waves

Seminar Organizer

Event Details

If even a relatively small number of primordial black holes (PBH) were created in the early universe, they will constitute an increasingly large fraction of the total energy density as space expands. It is thus well-motivated to consider scenarios in which the early universe was dominated by short lived PBH (M < 10^9 grams, t 10^11 GeV) to avoid overproduction. Furthermore, if the PBH undergo mergers before evaporating, the subsequent population acquires nonzero spin, so the resulting Kerr Hawking radiation efficiently produces gravitons whose contribution to ΔNeff is within the reach of future CMB experiments; such mergers also predict a characteristic spectrum of primordial gravitational waves at high frequencies correlated with the progenitor PBH mass.