Thermodynamics of Black Holes in Presence of String Instantons

TL;DR

This paper explores how coupling a Nambu-Goto string to gravity modifies black hole entropy, introducing a string tension-dependent correction due to quantum effects from string instantons.

Contribution

It demonstrates that string instantons cause a deviation from the standard entropy-area relation in black holes, incorporating string tension effects at the quantum level.

Findings

Black hole entropy is modified to $S=(A/4)(1-4\mu)$ due to string effects.

String instantons lead to horizon materialization at the quantum level.

The entropy-area relation is no longer universal in the presence of string instantons.

Abstract

The coupling of a Nambu-Goto string to gravity allows for Schwarzschild black holes whose entropy to area relation is $S=(A/4)(1-4\mu)$, where $\mu$ is the string tension. The departure from $A/4$ universality results from a string instanton which leads to a materialisation of the horizon at the quantum level.