Tunneling without barriers with gravity

TL;DR

This paper presents a new class of exact gravitational instanton solutions describing barrierless vacuum decay from Minkowski to anti-de Sitter space, with potential implications for cosmology and string theory.

Contribution

It introduces a one-parameter family of analytical instanton solutions for tunneling without barriers in gravity, extending previous non-gravitational results.

Findings

Analytical instanton solutions for barrierless tunneling with gravity.

Explicit calculation of the bounce action.

Discussion of implications for cosmology and string theory landscape.

Abstract

We consider the vacuum decay of the flat Minkowski space to an anti-de Sitter space. We find a one-parameter family of potentials that allow exact, analytical instanton solutions describing tunneling without barriers in the presence of gravity. In the absence of gravity such instantons were found and discussed by Lee and Weinberg more than a quarter of a century ago. The bounce action is also analytically computed. We discuss possible implications of these new instantons to cosmology in the context of the string theory landscape.