On the instability of Reissner-Nordstrom black holes in de Sitter backgrounds

TL;DR

This paper analytically proves the instability of higher-dimensional Reissner-Nordstrom-de Sitter black holes, providing insights into their instability mechanisms and confirming previous numerical findings.

Contribution

It offers an analytical proof of black hole instability in higher dimensions and calculates the instability timescale, complementing prior numerical studies.

Findings

Reissner-Nordstrom-de Sitter black holes are unstable in dimensions greater than 6.

Analytical computation of the instability timescale in the near-extremal limit.

Strong agreement between analytical results and previous numerical investigations.

Abstract

Recent numerical investigations have uncovered a surprising result: Reissner-Nordstrom-de Sitter black holes are unstable for spacetime dimensions larger than 6. Here we prove the existence of such instability analytically, and we compute the timescale in the near-extremal limit. We find very good agreement with the previous numerical results. Our results may me helpful in shedding some light on the nature of the instability.