Relic Gravitational Waves from String Cosmology

TL;DR

This paper explores the spectrum of relic gravitational waves predicted by string cosmology models, emphasizing their high-frequency tilt and potential detectability with upcoming gravitational-wave detectors.

Contribution

It provides estimates of the gravitational wave spectrum from string cosmology and identifies parameter regions accessible to planned detectors, advancing the understanding of early universe signals.

Findings

Relic gravitational wave spectrum is highly tilted towards high frequencies.

Certain parameter regions are within reach of planned detectors.

Detection prospects depend on specific cosmological parameters.

Abstract

A large class of string-cosmology backgrounds leads to a spectrum of relic stochastic gravitational waves, strongly tilted towards high frequencies, and characterized by two basic parameters of the cosmological model. We estimate the required sensitivity for detection of the predicted gravitational radiation and show that a region of our parameter space is within reach for some of the planned gravitational-wave detectors.