Proper fluctuations associated with quantum tunneling in field theory

TL;DR

This paper demonstrates that, at lowest order in 44, particle production during false vacuum decay via tunneling is governed by fluctuations orthogonal to the bounce solution, with implications illustrated through a homogeneous tunneling example.

Contribution

It introduces a new perspective on fluctuations in quantum tunneling, emphasizing the orthogonal component's role in particle production during false vacuum decay.

Findings

Particle production is linked to orthogonal fluctuations.

Orthogonal fluctuations dominate at lowest order in 44.

Homogeneous tunneling exemplifies the theoretical implications.

Abstract

It is shown that, to the lowest order in $\hbar,$ the particle production related to the tunneling that leads to the false vacuum decay is described by the orthogonal part of fluctuation field with respect to the bounce solution. As a simple example the spatially homogeneous tunneling is considered in order to illustrate the consequences coming from such a restriction of the fluctuation field.