Colliding Kaluza-Klein Bubbles

TL;DR

This paper presents an exact solution for the collision of Kaluza-Klein bubbles, revealing singularity formation hidden within an event horizon, and explores connections to Kerr black holes.

Contribution

It introduces a novel exact solution describing bubble collisions and links to Kerr black holes, expanding understanding of higher-dimensional spacetime dynamics.

Findings

Collision leads to a hidden curvature singularity within an event horizon.

The spacetime resembles the maximally extended Schwarzschild solution.

Inequivalent bubbles can be constructed from Kerr black holes.

Abstract

We construct an exact solution describing the collision of two Kaluza-Klein "bubbles of nothing" in 3+1 dimensions. When the bubbles collide, a curvature singularity forms which is hidden inside an event horizon. However, unlike the formation of ordinary black holes, in this case the spacetime resembles the entire maximally extended Schwarzschild solution. We also point out that there are inequivalent bubbles that can be constructed from Kerr black holes.