Statistical entropy of charged two-dimensional black holes

TL;DR

This paper computes the microscopic statistical entropy of a two-dimensional charged black hole using U-duality, confirming it matches thermodynamic calculations and extending previous results from higher-dimensional black holes.

Contribution

It introduces a U-duality-based method to derive the microscopic entropy of two-dimensional charged black holes, linking it to known higher-dimensional results.

Findings

Microscopic entropy matches thermodynamic calculations.

U-duality relates 2D black holes to higher-dimensional counterparts.

Extends microstate counting techniques to lower-dimensional black holes.

Abstract

The statistical entropy of a five-dimensional black hole in Type II string theory was recently derived by showing that it is U-dual to the three-dimensional Banados-Teitelboim-Zanelli black hole, and using Carlip's method to count the microstates of the latter. This is valid even for the non-extremal case, unlike the derivation which relies on D-brane techniques. In this letter, I shall exploit the U-duality that exists between the five-dimensional black hole and the two-dimensional charged black hole of McGuigan, Nappi and Yost, to microscopically compute the entropy of the latter. It is shown that this result agrees with previous calculations using thermodynamic arguments.