Rayleigh-Plateau and Gregory-Laflamme instabilities of black strings

TL;DR

This paper draws an analogy between black string instabilities and classical fluid instabilities, successfully reproducing key features and thresholds, and providing insights into black hole stability and dynamics.

Contribution

It introduces a membrane analogy to model black string instabilities, achieving accurate predictions of thresholds and timescales across dimensions.

Findings

Good agreement for the threshold mode in all dimensions

Exact agreement for large spacetime dimensionality

Instability timescale and dimensionality dependence are well described

Abstract

Many and very general arguments indicate that the event horizon behaves as a stretched membrane. We explore this analogy by associating the Gregory-Laflamme instability of black strings with a classical membrane instability known as Rayleigh-Plateau instability. We show that the key features of the black string instability can be reproduced using this viewpoint. In particular, we get good agreement for the threshold mode in all dimensions and exact agreement for large spacetime dimensionality. The instability timescale is also well described within this model, as well as the dimensionality dependence. We conjecture that general non-axisymmetric perturbations are stable. We further argue that the instability of ultra-spinning black holes follows from this model.