Detectability of Primordial Black Hole Binaries at High Redshift

TL;DR

This paper demonstrates that high-redshift primordial black hole binaries can be detected via gravitational waves, with detection prospects improved by redshift bias, clustering, and future space-based detectors, helping constrain dark matter composition.

Contribution

It introduces a model showing enhanced detectability of primordial black hole binaries at high redshift, considering clustering and redshift bias effects.

Findings

Detection of high-redshift PBH binaries is feasible with space-based GW detectors.

Redshift bias and clustering increase the effective detectable mass range.

Future GW observations can constrain PBH dark matter fraction and initial distribution.

Abstract

We show that the gravitational wave signals from primordial black hole (PBH) binaries at high redshift can be detected. The detectability of PBH binaries is enhanced by redshift bias and more PBH binaries at high redshift. The initial clustering of PBHs is also included and enhances the effectively detectable mass ranges of PBHs at high redshift. Future observations on the gravitational wave at high redshift by space-based detectors such as LISA and SKA can constrain the fraction of PBHs in dark matter and PBHs initial distribution.