On the primordial binary black hole mergings in LIGO-Virgo-Kagra data

Abstract

We briefly discuss a possible cosmological implication of the observed binary black hole mergings detected by LIGO-Virgo-Kagra collaboration (GWTC-3 catalogue) for the primordial black hole (PBH) formation in the early Universe. We show that the bumpy chirp mass distribution of the LVK BH+BH binaries can be fit with two distinct and almost equal populations: (1) astrophysical mergings from BH+BH formed in the modern Universe from evolution of massive binaries and (2) mergings of binary PBHs with initial log-normal mass distribution. We find that the PBH central mass (M c 30M ) and distribution width derived from the observed LVK chirp masses are almost insensitive to the assumed double PBH formation model. To comply with the observed LVK BH+BH merging rate, the CDM PBH mass fraction should be f pbh ∼ 10 −3 but can be higher if PBH clustering is taken into account.

Impact of dark matter spikes on the merger rates of Primordial Black Holes

“…In the mass range probed by the LVK Collaboration, we know that the fractional abundance f pbh of PBHs in cold dark matter (CDM) should not be greater than ∼ 10 −3 [10,[26][27][28][29][30][31][32][33][34][35][36][37][38][39]. This implies the existence of other candidates contributing to the dark matter, which may have a particle nature.…”