Detection Prospects of Gravitational Waves from SU(2) Axion Inflation

TL;DR

This paper evaluates the potential to detect gravitational waves from SU(2) axion inflation, considering observational constraints and future detector sensitivities, and establishes current bounds on model parameters.

Contribution

It provides a comprehensive analysis of detection prospects for gravitational waves from SU(2) axion inflation, incorporating all relevant observational constraints and exploring conditions for future detectability.

Findings

Current LIGO-Virgo-KAGRA data do not show evidence of such gravitational waves.

Conservative bounds on SU(2) inflation parameters are established based on existing data.

Future third-generation detectors could potentially observe signals consistent with certain inflationary models.

Abstract

We study detection prospects of a gravitational-wave background (GWB) sourced by SU(2) gauge fields considering all possible observational constraints. More precisely, we consider bounds set by cosmic microwave background measurements, primordial black hole overproduction, as well as backreaction of the gauge fields on the background evolution. Gravitational-waves data from the first three observing runs of the LIGO-Virgo-KAGRA Collaboration show no evidence for a GWB contribution from axion inflation. However, we are able to place conservative constraints on the parameters of the SU(2) inflation with current data. We investigate conditions on the inflationary potential that would lead to a detectable signal that evades astrophysical and cosmological constraints and discuss detection prospects for third generation networks.