Properties of the magnetised Kaluza-Klein bubble

TL;DR

This paper analyzes a magnetized Kaluza-Klein bubble spacetime, revealing its derivation, physical properties, and thermodynamic behavior, including negative mass solutions and solution branches, drawing parallels to Anti-de Sitter-Melvin configurations.

Contribution

It provides a detailed derivation and analysis of a magnetized Kaluza-Klein bubble, highlighting its unique properties and thermodynamic characteristics compared to prior models.

Findings

Solution can have negative mass for certain magnetic fields.

Two solution branches exist for a given magnetic flux.

Lower mass branch is thermodynamically favored.

Abstract

In this paper we study a Kaluza-Klein bubble-type spacetime with a magnetic field first obtained by Sarbach and Lehner in 2005. It is shown that this solution can be derived via a Harrison transformation of a vacuum Kaluza-Klein bubble, and its physical and geometrical quantities are determined. For certain ranges of the magnetic field parameter, this solution carries negative mass. Furthermore, for a given value of magnetic flux, there exist two branches of solutions, and the branch with lower mass is thermodynamically favoured. In light of these properties we interpret the spacetime as another analogue to the Anti-de Sitter-Melvin solution.