Decay of Kaluza-Klein Vacuum via Singular Instanton

TL;DR

This paper investigates how singular instanton solutions influence the decay rate of a five-dimensional Kaluza-Klein vacuum, revealing that solutions with conical singularities lead to faster decay, impacting theories with compact extra dimensions.

Contribution

It introduces the analysis of singular bounce solutions in vacuum decay, showing their dominant role compared to regular solutions in Kaluza-Klein theories.

Findings

Singular instantons increase decay rates compared to regular solutions.

Conical singularities significantly affect vacuum stability.

Thermodynamic perspective supports enhanced decay rates.

Abstract

In the decay process of metastable vacua in quantum field theories, the bounce solution, a classical solution in Euclideanized theories, is helpful in calculating the decay rate. Recently, the bounce solution with a conical singularity has attracted wide attention and revealed physical importance. In this paper, we discuss the bubble of nothing solution, which describes the decay process of a five-dimensional Kaluza-Klein vacuum, and study the consequence of including conical singularity. We found that the bounce solution with singularities has a higher decay rate than those without. This effect suggests that a singular solution can play a dominant role in vacuum decay of theories with compact internal space. We also discuss the enhanced decay rate from a thermodynamic perspective.