Black holes and gravitational waves in string cosmology

TL;DR

This paper discusses how string cosmology models predict a gravitational wave background that could be detectable and is linked to primordial black hole formation, offering potential observational tests for these theories.

Contribution

It highlights the connection between gravitational wave spectra and density perturbations in string cosmology, proposing simultaneous detection as evidence for the model.

Findings

Gravitational wave spectrum grows with decreasing wavelength.

Detectable gravitational waves are linked to primordial black hole density.

Observation of both would support string cosmology models.

Abstract

Pre--big bang models of inflation based on string cosmology produce a stochastic gravitational wave background whose spectrum grows with decreasing wavelength, and which may be detectable using interferometers such as LIGO. We point out that the gravitational wave spectrum is closely tied to the density perturbation spectrum, and that the condition for producing observable gravitational waves is very similar to that for producing an observable density of primordial black holes. Detection of both would provide strong support to the string cosmology scenario.