Gauge-independence of tunneling rates

TL;DR

This paper demonstrates that tunneling rates can be consistently defined using a false-vacuum effective action, which remains gauge-independent due to Nielsen identities, providing a nonperturbative framework that clarifies convexity and radiative correction issues.

Contribution

It introduces a gauge-invariant, nonperturbative method to compute tunneling rates via the false-vacuum effective action evaluated at a quantum bounce.

Findings

Tunneling rates are gauge-independent due to Nielsen identities.

False-vacuum effective action can be used to define tunneling rates.

The approach clarifies convexity and radiative correction issues in tunneling calculations.

Abstract

It is shown that tunneling rates can be defined in terms of a false-vacuum effective action whose reality and convexity properties differ from those of the corresponding groundstate functional. The tunneling rate is directly related to the false-vacuum effective action evaluated at an extremal "quantum bounce". The Nielsen identities of the false-vacuum functional ensure that the rate remains independent of the choice of gauge-fixing. Our results are nonperturbative and clarify issues related with convexity and radiative corrections.