Dyon Spectrum in Generic N=4 Supersymmetric Z_N Orbifolds

TL;DR

This paper calculates the exact spectrum of certain BPS dyons in N=4 supersymmetric Z_N orbifolds and compares the statistical entropy with black hole entropy, including higher-derivative corrections.

Contribution

It provides the exact dyon spectrum and matches statistical entropy with black hole entropy incorporating four-derivative corrections in a broad class of N=4 orbifold models.

Findings

Exact quarter BPS dyon spectrum derived.

Asymptotic statistical entropy matches black hole entropy.

Higher-derivative corrections are essential for precise agreement.

Abstract

We find the exact spectrum of a class of quarter BPS dyons in a generic N=4 supersymmetric Z_N orbifold of type IIA string theory on K3\times T^2 or T^6. We also find the asymptotic expansion of the statistical entropy to first non-leading order in inverse power of charges and show that it agrees with the entropy of a black hole carrying same set of charges after taking into account the effect of the four derivative Gauss-Bonnet term in the effective action of the theory.