Black hole masking and black hole thermodynamics

TL;DR

This paper explores the phenomenon of black hole masking, where different black hole configurations share the same observable properties, and links it to black hole thermodynamics in finite cavities, revealing conditions for masking based on stability.

Contribution

It establishes a one-to-one correspondence between black hole masking and the existence of unstable solutions in black hole thermodynamics within finite cavities.

Findings

Masking occurs if and only if unstable black hole solutions exist.

Black hole thermodynamics in finite cavities explains masking phenomena.

The study links observable black hole data to underlying stability conditions.

Abstract

Masking of black holes means that, for given total mass and Hawking temperatures, these data may correspond to either "pure" black hole or a black hole of a lesser mass surrounded by a massive shell. It is shown that there is one-to one correspondence between this phenomenon and thermodynamics of a black hole in a finite size cavity: masking of black holes is possible if and only if there exists at least one locally unstable black hole solution in the corresponding canonical ensemble.