Vacua on the Brink of Decay

TL;DR

This paper investigates the behavior of quantum fields near vacuum decay thresholds in various backgrounds, revealing a universal singular term in the effective action that dominates decay rates and relates to critical gravitational phenomena.

Contribution

It identifies a universal singular term in the effective action at the brink of vacuum decay, linking quantum field theory with gravitational critical phenomena.

Findings

Universal singular term in effective action near decay threshold

Singular term dominates vacuum decay rate when tuned above instability

Connection between quantum decay and Choptuik scaling in gravity

Abstract

We consider free massive matter fields in static scalar, electric and gravitational backgrounds. Tuning these backgrounds to the brink of vacuum decay, we identify a term in their effective action that is singular. This singular term is universal, being independent of the features of the background configuration. In the case of gravitational backgrounds, it can be interpreted as a quantum mechanical analog of Choptuik scaling. If the background is tuned slightly above the instability threshold, this singular term gives the leading contribution to the vacuum decay rate.