Fate of Kaluza-Klein Black Holes: Evaporation or Excision?

TL;DR

This paper investigates the evaporation process of Kaluza-Klein black holes, revealing that their internal space deforms significantly during evaporation and may be excised before instability occurs.

Contribution

It introduces a new analysis of black string evaporation considering backreaction, showing potential excision of Kaluza-Klein black holes prior to instability.

Findings

Internal space becomes necked during evaporation

Deformation increases as evaporation proceeds

Black holes may be excised before Gregory-Laflamme instability

Abstract

We study evaporation process of black strings which are typical examples of Kaluza-Klein black holes. Taking into account the backreaction of the Hawking radiation, we deduce the evolution equation for the radion field. By solving the evolution equation, we find that the shape of the internal space is necked by the Hawking radiation and the amount of the deformation becomes large as the evaporation proceeds. Based on this analysis, we speculate that the Kaluza-Klein black holes would be excised from the Kaluza-Klein spacetime before the onset of the Gregory-Laflamme instability and therefore before the evaporation.