Spins of primordial black holes formed in different cosmological scenarios

Understand

Primordial black holes (PBHs) could account for all or part of dark matter, as well as for some LIGO events.

• We discuss the spins of primordial black holes produced in different cosmological scenarios, with the emphasis on recently discovered possibilities.
• PBHs produced as a horizon-size collapse of density perturbations are known to have very small spins.
• In contrast, PBHs resulting from assembly of matterlike objects (particles, Q-balls, oscillons, etc.) can have large or small spins depending on their formation history and the efficiency of radiative cooling.