Eliminating the LIGO bounds on primordial black hole dark matter

Primordial black holes (PBHs) in the mass range (30-100) M-circle dot are interesting candidates for dark matter but are tightly constrained by the LIGO merger rate. In deriving these constraints, PBHs were treated as constant Schwarzschild masses. A careful analysis of cosmological black holes however leads to a time-dependent effective mass. This implies stricter conditions for binary formation, so that the binaries formed merge well before LIGO's observations. The observed binaries are those coalescing within galactic halos, at a rate consistent with LIGO data. This reopens the possibility of LIGO mass PBH dark matter.

Automated summary

A study suggests that cosmological black holes have a time-dependent effective mass, leading to stricter conditions for binary formation. This implies that binaries observed by LIGO must merge earlier than previously thought, reopening the possibility of LIGO mass PBH dark matter.