Bounces with O(3) x O(2) symmetry

TL;DR

This paper investigates the decay of de Sitter vacua via bounces with O(3) x O(2) symmetry, revealing their relation to thermal bubble production, their approach to Hawking-Moss solutions, and the limitations of the thin-wall approximation.

Contribution

It provides a detailed numerical analysis of O(3) x O(2) symmetric bounces, comparing their Euclidean action to O(4) symmetric solutions and examining their behavior near the horizon.

Findings

Bounces approach Hawking-Moss solutions as gravity or vacuum energy increase.

Euclidean action of these bounces exceeds that of O(4) symmetric Coleman-De Luccia bounces.

Thin-wall approximation breaks down when the bubble wall nears the horizon.

Abstract

We study the contribution to the decay of de Sitter vacua from bounces with O(3) x O(2) symmetry. These correspond to the thermal production of a vacuum bubble at the center of a horizon volume with radius r_H and a temperature defined by the horizon. They are analogues of the flat spacetime bounces, independent of Euclidean time, that correspond to thermal production of a critical bubble. If either the strength of gravity or the false vacuum energy are increased, with all other parameters held fixed, the bounces approach, and eventually merge with, the Hawking-Moss solution. Increasing the height of the barrier separating the true and false vacuum, and thus the tension in the bubble wall, causes the center of the bubble wall to approach, but never reach, the horizon. This is in contrast with the prediction of the thin-wall approximation, which inevitably breaks down when the wall is near the horizon. Our numerical results show that the Euclidean action of our solutions is always greater than that of the corresponding O(4)-symmetric Coleman-De Luccia bounce.