Constraining high-redshift stellar-mass primordial black holes with next-generation ground-based gravitational-wave detectors [article]

Ken K. Y. Ng, Gabriele Franciolini, Emanuele Berti, Paolo Pani, Antonio Riotto, Salvatore Vitale
2022 arXiv   pre-print
The possible existence of primordial black holes in the stellar mass window has received considerable attention because their mergers may contribute to current and future gravitational-wave detections. Primordial black hole mergers, together with mergers of black holes originating from Population III stars, are expected to dominate at high redshifts (z≳ 10). However the primordial black hole merger rate density is expected to rise monotonically with redshift, while Population III mergers can
more » ... y occur after the birth of the first stars. Next-generation gravitational-wave detectors such as Cosmic Explorer (CE) and Einstein Telescope (ET) can access this distinctive feature in the merger rates as functions of redshift, allowing for a direct measurement of the abundance of the two populations, and hence for robust constraints on the abundance of primordial black holes. We simulate four-months worth of data observed by a CE-ET detector network and perform hierarchical Bayesian analysis to recover the merger rate densities. We find that if the Universe has no primordial black holes with masses of 𝒪(10M_⊙), the projected upper limit on their abundance f_ PBH as a fraction of dark matter energy density may be as low as f_ PBH∼𝒪(10^-5), about two orders of magnitude lower than current upper limits in this mass range. If instead f_ PBH≳ 10^-4, future gravitational wave observations would exclude f_ PBH=0 at the 95% credible interval.
arXiv:2204.11864v1 fatcat:pocmu3s5vzcufoufxn7y6c7dsy