Occurrence of semiclassical vacuum decay

TL;DR

This paper explores how semiclassical vacuum decay can occur through large initial fluctuations in field velocity, even without localized large velocities, expanding understanding of vacuum decay mechanisms.

Contribution

It demonstrates that large-scale initial velocity profiles can induce vacuum decay semiclassically, even without localized large velocities, broadening the conditions for decay.

Findings

Large initial velocity regions can trigger vacuum decay.

Semiclassical decay is possible without localized large velocities.

The spatial extent of velocity fluctuations influences decay likelihood.

Abstract

Recently, a novel phenomenon is observed for vacuum decay to proceed via classically allowed dynamical evolution from initial configurations of false vacuum fluctuations. With the help of some occasionally developed large fluctuations in time derivative of a homogeneous scalar field that is initially sitting at the false vacuum, the flyover vacuum decay is proposed if the initial Gaussian profile of field velocity contains a spatial region where the field velocity is large enough to flyover the potential barrier. In this paper, we point out that, even if the initial profile of field velocity is nowhere to be large enough to classically overcome the barrier, the semiclassical vacuum decay could still be possible if the initial profile of field velocity extends over large enough region.