Counting States of Black Strings with Traveling Waves II

TL;DR

This paper extends the analysis of extremal black string entropy by including angular momentum and additional dimensions, confirming the microscopic state count matches the macroscopic entropy.

Contribution

It introduces new calculations for black strings with angular momentum and in five dimensions, expanding previous work on traveling wave solutions.

Findings

Horizon remains homogeneous with added angular momentum.

Computed horizon area matches entropy predictions.

Microscopic BPS state count agrees with macroscopic entropy.

Abstract

We extend our recent analysis of the entropy of extremal black strings with traveling waves. We previously considered waves carrying linear momentum on black strings in six dimensions. Here we study waves carrying angular momentum on these strings, and also waves carrying linear momentum on black strings in five dimensions. In both cases, we show that the horizon remains homogeneous and compute its area. We also count the number of BPS states at weak string coupling with the same distribution of linear and angular momentum, and find complete agreement with the black string entropy.