Gravitational waves from deflagration bubbles in first-order phase transitions

TL;DR

This paper models gravitational wave production from turbulence caused by deflagration bubbles during a first-order phase transition, highlighting potential detectability by LISA in electroweak baryogenesis scenarios.

Contribution

It provides a detailed calculation of gravitational radiation from turbulence during deflagration bubble-driven phase transitions, including shock front effects.

Findings

Peak gravitational wave energy density $ o 10^{-9}$

Detectability prospects for LISA in electroweak transition

Wall velocities $v_w \\lesssim 0.1$ favor baryogenesis

Abstract

The walls of bubbles in a first-order phase transition can propagate either as detonations, with a velocity larger than the speed of sound, or deflagrations, which are subsonic. We calculate the gravitational radiation that is produced by turbulence during a phase transition which develops via deflagration bubbles. We take into account the fact that a deflagration wall is preceded by a shock front which distributes the latent heat throughout space and influences other bubbles. We show that turbulence can induce peak values of $\Omega_{GW}$ as high as $\sim 10^{-9}$. We discuss the possibility of detecting at LISA gravitational waves produced in the electroweak phase transition with wall velocities $v_w\lesssim 10^{-1}$, which favor electroweak baryogenesis.