"the Instability of String-Theoretic Black Holes"

TL;DR

This paper demonstrates that static, charged black holes in string theory are classically unstable to linear perturbations, with unstable modes appearing even at small positive charges, contrasting with the stability of similar black holes in general relativity.

Contribution

It reveals a fundamental classical instability of string-theoretic black holes that is absent in their general relativity counterparts, highlighting differences in stability properties.

Findings

String-theoretic black holes are classically unstable to linear perturbations.

Unstable modes appear for arbitrarily small positive charges.

This instability is distinct from quantum evaporation effects.

Abstract

It is demonstrated that static, charged, spherically--symmetric black holes in string theory are classically and catastrophically unstable to linearized perturbations in four dimensions, and moreover that unstable modes appear for arbitrarily small positive values of the charge. This catastrophic classical instability dominates and is distinct from much smaller and less significant effects such as possible quantum mechanical evaporation. The classical instability of the string--theoretic black hole contrasts sharply with the situation which obtains for the Reissner--Nordstr\"om black hole of general relativity, which has been shown by Chandrasekhar to be perfectly stable to linearized perturbations at the event horizon.