An Exploration of Vacuum-Decay Valleys

TL;DR

This paper investigates the complex structure of vacuum decay in single-field potentials, revealing the existence of pseudo-bounces, antibounces, and multiple bounce configurations, which extend the traditional understanding of vacuum decay mechanisms.

Contribution

It uncovers a richer vacuum decay landscape, including pseudo-bounces and multiple bounce solutions, using combined Euclidean and tunneling potential methods.

Findings

Existence of pseudo-bounce decay configurations.

Multiple bounce solutions including antibounces.

Vacuum decay structure is more complex than traditional models.

Abstract

In the standard lore the decay of the false vacuum of a single-field potential is described by a semi-classical Euclidean bounce configuration that can be found using overshoot/undershoot algorithms, and whose action suppresses exponentially the decay rate. While this is generically correct, we show in a few concrete examples of potentials, previously studied in the literature for other purposes, that the vacuum decay structure can be far richer. In some cases there is no bounce and decay proceeds via the so-called pseudo-bounce configurations. In the general case with bounce, there are $2n+1$ bounces, with $n$ ranging from 0 (the standard case) to $\infty$. Some of these decay configurations we call antibounces as they have the wrong behavior for overshoot/undershoot algorithms, which can miss them. Bounce and antibounce configurations form $n$ pairs connected by pseudo-bounces. Our analysis benefits from a combined use of Euclidean and tunneling potential methods.