Bubble wall perturbations coupled with gravitational waves

TL;DR

This paper investigates the interaction between gravitational waves and a vacuum bubble wall in de Sitter space, revealing that gravitational backreaction influences bubble wall oscillations.

Contribution

It introduces a coupled system analysis of gravitational waves and bubble walls using Israel's metric junction formalism, highlighting the importance of backreaction effects.

Findings

Bubble wall oscillations occur only during gravitational wave passage.

Gravitational backreaction affects bubble wall dynamics.

The dynamical degree of the bubble wall is effectively lost.

Abstract

We study a coupled system of gravitational waves and a domain wall which is the boundary of a vacuum bubble in de Sitter spacetime. To treat the system, we use the metric junction formalism of Israel. We show that the dynamical degree of the bubble wall is lost and the bubble wall can oscillate only while the gravitational waves go across it. It means that the gravitational backreaction on the motion of the bubble wall can not be ignored.