Direct Detection of Primordial Gravitational Waves in a BSI Inflationary Model

TL;DR

This paper explores the potential for future space interferometers to directly detect the stochastic gravitational wave background generated during inflation in a specific class of cosmological models, finding that the signals are close but likely not detectable soon.

Contribution

It demonstrates that certain viable inflationary models produce a gravitational wave background stronger than single-field slow-roll models, providing new insights into inflationary predictions for GW detection.

Findings

Maximal GW energy density around 3×10^{-15} at 10^{-3}Hz

Detection prospects are limited as signals are near current sensitivity thresholds

Improved models could enhance detectability of primordial GWs

Abstract

We investigate the possibility for a direct detection by future space interferometers of the stochastic gravitational wave (GW) background generated during the inflationary stage in a class of viable $\Lambda$CDM BSI models. At frequencies around $10^{-3}$Hz, maximal values $\Omega_{gw}(\nu)\sim 3\times 10^{-15}$ are found, an improvement of about one order of magnitude compared to single-field, slow-roll inflationary models. This is presumably not sufficient in order to be probed in the near future.