Stability of axion-saxion wormholes

Abstract

We reconsider the perturbative stability of Euclidean axion wormholes. The quadratic action that governs linear perturbations is derived directly in Euclidean gravity. We demonstrate explicitly that a stability analysis in which one treats the axion as a normal two-form gauge field is equivalent to one performed in the Hodge-dual formulation, where one considers the axion as a scalar with a wrong-sign kinetic term. Both analyses indicate that axion wormholes are perturbatively stable, even in the presence of a massless dilaton, or saxion, field that couples to the axion.