Gravitational Radiation from First-Order Phase Transitions

TL;DR

This paper uses high-resolution lattice simulations to study gravitational waves from first-order phase transitions, revealing that bubble coalescence enhances gravitational radiation, which could improve prospects for detecting electroweak phase transition signals.

Contribution

It introduces a novel simulation approach to quantify gravitational radiation from bubble coalescence during phase transitions, highlighting an enhancement effect previously unaccounted for.

Findings

Bubble coalescence increases gravitational wave production.

Simulation results suggest easier detection of electroweak phase transition signals.

Enhancement effect is independent of fluid or turbulence presence.

Abstract

It is believed that first-order phase transitions at or around the GUT scale will produce high-frequency gravitational radiation. This radiation is a consequence of the collisions and coalescence of multiple bubbles during the transition. We employ high-resolution lattice simulations to numerically evolve a system of bubbles using only scalar fields, track the anisotropic stress during the process and evolve the metric perturbations associated with gravitational radiation. Although the radiation produced during the bubble collisions has previously been estimated, we find that the coalescence phase enhances this radiation even in the absence of a coupled fluid or turbulence. We comment on how these simulations scale and propose that the same enhancement should be found at the Electroweak scale; this modification should make direct detection of a first-order electroweak phase transition easier.