Quasinormal Modes and Stability of Firewalls

TL;DR

This paper examines the stability of firewall models in black holes, analyzing how perturbations affect their structure and constraining their parameters to ensure physical plausibility.

Contribution

It provides a detailed stability analysis of firewall models, especially under perturbations, and establishes parameter constraints for their viability.

Findings

Stability constraints limit firewall internal parameters.

Subluminal sound speed conditions restrict model configurations.

Firewall models can be stable under certain parameter ranges.

Abstract

A solution to the black hole information problem requires propagation of information from the interior of the black hole to the exterior. Such propagation violates general relativity and could conceivably be accomplished through "firewall" models. Based on the existence of similar firewalls at the inner horizons of charged and rotating black holes, a model of a firewall was recently constructed where the exterior spacetime reduces to that of the Schwarzschild metric but with a dramatically different interior. We investigate the radial and nonradial polar stability of these objects. We first study the dynamics of the shell under spherically symmetric perturbations, and impose constraints on the firewall model parameters by requiring a subluminal speed of sound on the firewall. We show that the demands of stability and subluminality impose significant constraints on the internal parameters of the firewall, narrowing down the range of objects that could be used to create such a structure.