Background of gravitational waves from pre-galactic black hole formation

TL;DR

This paper investigates the stochastic gravitational wave background generated by early black hole formation from supernovae during the universe's structure formation, highlighting potential for extracting cosmological information from GW observations.

Contribution

It models the GW background from pre-galactic black holes formed at high redshifts and discusses how GW detection could reveal details of early universe events.

Findings

Maximum GW background amplitude of ~10^{-24} at 30-470 Hz

GW background depends on formation redshifts and efficiency

Potential to determine emission epoch from GW spectrum

Abstract

We study the generation of a gravitational wave (GW) background produced from a population of core-collapse supernovae, which form black holes in scenarios of structure formation of the Universe. We obtain, for example, that a pre-galactic population of black holes, formed at redshifts $z\simeq 30-10$, could generate a stochastic GW background with a maximum amplitude of $h_{\rm BG}\simeq 10^{-24}$ in the frequency band $\nu_{\rm obs}\simeq 30-470 {\rm Hz}$ (considering a maximum efficiency of generation of GWs, namely, $\epsilon_{\rm GW}=7\times 10^{-4}$). In particular, we discuss what astrophysical information could be obtained from a positive, or even a negative, detection of such a GW background produced in scenarios such as those studied here. One of them is the possibility of obtaining the initial and final redshifts of the emission period from the observed spectrum of GWs.