Vacuum tunneling in gravity

TL;DR

This paper explores vacuum tunneling in gravity models with non-trivial topology, using Cartan variables like vielbein and contortion, and demonstrates possible tunneling mechanisms via gravitational instantons and quantum fluctuations.

Contribution

It introduces a novel approach to vacuum tunneling in gravity by incorporating Cartan variables and self-dual contortion configurations, expanding understanding of quantum gravitational phenomena.

Findings

Tunneling between topological vacuums via Eguchi-Hanson instanton.

Contortion quantum fluctuations can facilitate vacuum tunneling.

Explicit self-dual contortion configurations are constructed.

Abstract

Topologically non-trivial vacuum structure in gravity models with Cartan variables (vielbein and contortion) is considered. We study the possibility of vacuum space-time tunneling in Einstein gravity assuming that the vielbein may play a fundamental role in quantum gravitational phenomena. It has been shown that in the case of RP3 space topology the tunneling between non-trivial topological vacuums can be realized by means of Eguchi-Hanson gravitational instanton. In Riemann-Cartan geometric approach to quantum gravity the vacuum tunneling can be provided by means of contortion quantum fluctuations. We define double self-duality condition for the contortion and give explicit self-dual configurations which can contribute to vacuum tunneling amplitude.