The merger rate of primordial-black-hole binaries

Understand

Primordial black holes (PBHs) have long been a candidate for the elusive dark matter (DM), and remain poorly constrained in the ~20-100 Msun mass range.

• PBH binaries were recently suggested as the possible source of LIGO's first detections.
• In this paper, we thoroughly revisit existing estimates of the merger rate of PBH binaries.
• We compute the probability distribution of orbital parameters for PBH binaries formed in the early Universe, accounting for tidal torquing by all other PBHs, as well as standard large-scale adiabatic perturbations.