Quantisation Across Bubble Walls and Friction

TL;DR

This paper develops a first-principles quantisation framework for field theories on bubble walls, focusing on gauge symmetry breaking, and computes momentum transfer from transition radiation with implications for cosmological phase transitions.

Contribution

It introduces a novel quantisation approach for fields on bubble walls and calculates transition radiation effects, including polarization-specific momentum transfer, in symmetry-breaking transitions.

Findings

Longitudinal polarisation emission is comparable to transverse in mild super-cooling.

In broken to broken transitions with thin walls, longitudinal emission dominates.

Framework enables robust calculations of particle processes in translation-breaking backgrounds.

Abstract

We quantise from first principles field theories living on the background of a bubble wall in the planar limit with particular focus on the case of spontaneous breaking of gauge symmetry. Using these tools, we compute the average momentum transfer from transition radiation: the soft emission of radiation by an energetic particle passing across the wall, with a particular focus on the longitudinal polarisation of vectors. We find these to be comparable to transverse polarisations in symmetry-breaking transitions with mild super-cooling, and dominant in broken to broken transitions with thin wall. Our results have phenomenological applications for the expansion of bubbles during first order phase transitions. Our general framework allows for the robust calculation of any particle processes of interest in such translation breaking backgrounds.