Non-Axisymmetric Instability of Rotating Black Holes in Higher Dimensions

TL;DR

This paper identifies a new non-axisymmetric instability in higher-dimensional rotating black holes, which dominates previously known instabilities and impacts the understanding of black hole phase structures.

Contribution

It discovers a novel bar-mode instability in Myers-Perry black holes in odd dimensions, extending the stability analysis beyond axisymmetric perturbations.

Findings

Identifies a new bar-mode instability for D ≥ 7.

Instability occurs at slower spins than previously known.

Implications for the phase diagram of higher-dimensional black holes.

Abstract

We calculate the scalar-gravitational quasi-normal modes of equal angular momenta Myers-Perry black holes in odd dimensions. We find a new bar-mode (non-axisymmetric) classical instability for $D \ge 7$. These black holes were previously found to be unstable to axisymmetric perturbations for spins very near extremality. The bar-mode instability we find sets in at much slower spins, and is therefore the dominant instability of these black holes. This instability has important consequences for the phase diagram of black holes in higher dimensions.