Strong Cosmic Censorship and the Universal Relaxation Bound

TL;DR

This paper proves the strong cosmic censorship conjecture holds in non-asymptotically flat de Sitter black-hole spacetimes using thermodynamic principles, supporting the idea that Cauchy horizons are unstable.

Contribution

It provides a general proof of the strong cosmic censorship conjecture in de Sitter black holes based on Bekenstein's generalized second law.

Findings

Cauchy horizons are unstable in de Sitter black holes

The proof is based on thermodynamic laws

Supports the validity of cosmic censorship in these spacetimes

Abstract

The strong cosmic censorship conjecture, introduced by Penrose five decades ago, asserts that, in self-consistent theories of gravity, Cauchy horizons inside dynamically formed black holes should be unstable to remnant perturbation fields that fall into the newly born black holes. The question of the (in)validity of this intriguing conjecture in non-asymptotically flat charged black-hole spacetimes has recently attracted much attention from physicists and mathematicians. We here provide a general proof, which is based on Bekenstein's generalized second law of thermodynamics, for the validity of this fundamental conjecture in non-asymptotically flat de Sitter black-hole spacetimes.