Euclidean wormholes stability analysis revisited

TL;DR

This paper revisits the stability analysis of Euclidean axion wormholes, demonstrating that previous divergences were artifacts and that the wormholes remain stable when all modes are properly included, using a new analytical technique.

Contribution

It corrects previous stability analyses by including symmetric modes with finite actions and introduces a pseudo-analytic method for assessing mode positivity.

Findings

Symmetric modes have finite actions when constraints are fully solved.

Including these modes does not alter the wormholes' stability conclusions.

A new technique simplifies stability analysis without heavy numerics.

Abstract

Previous studies of linearized stability of asymptotically flat Euclidean axion wormholes found that symmetric modes suffered from divergences. We show that such divergences were an artifact of a particular way of solving the constraints, and that a full treatment leads to finite actions for such modes. The modes must thus be included in a stability analysis. However, since the action for these modes turns out to be positive, this turns out not to affect previous statements about stability of axion wormholes. We also introduce a technique that allows us to show this positivity at a pseudo-analytic level that avoids heavy numerics. Our techniques should be useful to future studies of stabilities of other wormholes as well.