Analytic bounces in d dimensions

TL;DR

This paper generalizes the analytical calculation of Euclidean bounce actions for scalar fields with various potential barriers from four to d dimensions, including cases with damped oscillations when the true vacuum is unreachable.

Contribution

It provides explicit formulas for bounce actions in d dimensions for triangular, square, and quadratic barriers, extending previous four-dimensional results.

Findings

Analytic formulas for bounce actions in d dimensions.

Reduction to thin wall approximation when vacua are close.

Analysis of damped oscillations in Lorentzian spacetime.

Abstract

We study the Euclidean bounce action interpolating between a false and a true vacuum for a scalar field theory with various types of potential. We focus on the cases of a triangular, a square and a quadratic barrier, where the bounce action has already been computed analytically in four dimensions. We generalize the result to d dimensions, providing an analytic formula in each case. Furthermore we show that our results reduce to the ones computed from the thin wall approximation, when the true and the false vacuum are close in energy. When the true vacuum cannot be reached in a finite amount of Euclidean time we study the damped oscillations of the solution by analytical continuation to Lorentzian spacetime.