Dissipative Effects as New Observables for Cosmological Phase Transitions

TL;DR

This paper demonstrates that dissipative effects during cosmological first order phase transitions suppress high-frequency gravitational wave signals, altering their spectral shape and peak, thus providing new observational probes of particle interactions.

Contribution

It introduces an analytical model showing how dissipation affects gravitational wave spectra from cosmological phase transitions, revealing new observables for particle physics.

Findings

Dissipative effects cause frequency-dependent suppression of gravitational waves.

Spectral shape and peak frequency are modified by dissipation.

Potential to extract particle interaction information from gravitational wave spectra.

Abstract

We show that dissipative effects during cosmological first order phase transitions lead to a frequency-dependent suppression for the usually dominant gravitational wave production from sound waves, through an analytical modelling of the source based on the sound shell model. This damping effect is more pronounced for high frequencies or small scales, and modifies the spectral shape and possibly the peak frequency. These modifications can be used to reveal more information about the underlying particle interactions, serving as a way of breaking the parameter degeneracy that plagues particle physics studies based on the perfect fluid approximation.