Gravitational traces of broken gauge symmetries

TL;DR

This paper studies how hidden sector phase transitions in the early universe can produce gravitational waves detectable by interferometers, focusing on models with broken gauge symmetries and the effects of bubble wall friction.

Contribution

It analyzes the impact of bubble wall friction on gravitational wave signals in two simplified models of hidden sector phase transitions, providing insights for future detections.

Findings

Friction effects significantly alter gravitational wave spectra.

Potential to distinguish underlying theories from gravitational wave signals.

Implications for current and future gravitational wave detectors.

Abstract

We investigate first order phase transitions arising from hidden sectors which are in thermal equilibrium with the Standard Model bath in the Early Universe. Focusing on two simplified scenarios, an higgsed U(1) and a two scalar singlet model, we show the impact of friction effects acting on the bubble walls on the gravitational wave spectra and on the consequences for present and future interferometer experiments. We further comment on the possibility of disentangling the properties of the underlying theory featuring the first order phase transition should a stochastic gravitational wave signal be discovered.