alpha'-Corrections to Extremal Dyonic Black Holes in Heterotic String Theory

TL;DR

This paper calculates the entropy of extremal dyonic black holes in heterotic string theory, incorporating all tree-level four-derivative corrections, and confirms previous results for both supersymmetric and non-supersymmetric cases.

Contribution

It provides a comprehensive computation of black hole entropy including all relevant four-derivative corrections, extending previous partial results and confirming their validity.

Findings

Entropy matches earlier results for supersymmetric black holes

Entropy agrees with AdS_3 near horizon geometry assumptions for non-supersymmetric cases

All four-derivative corrections are explicitly included in the entropy calculation

Abstract

We explicitly compute the entropy of an extremal dyonic black hole in heterotic string theory compactified on T^6 or K3\times T^2 by taking into account all the tree level four derivative corrections to the low energy effective action. For supersymmetric black holes the result agrees with the answer obtained earlier 1) by including only the Gauss-Bonnet corrections to the effective action 2) by including all terms related to the curvature squared terms via space-time supersymmetry transformation, and 3) by using general arguments based on the assumption of AdS_3 near horizon geometry and space-time supersymmetry. For non-supersymmetric extremal black holes the result agrees with the one based on the assumption of AdS_3 near horizon geometry and space-time supersymmetry of the underlying theory.