Non-extremal Stringy Black Hole

TL;DR

This paper constructs a non-extremal stringy black hole solution in four dimensions, evaluates its entropy semiclassically, and relates it to microscopic string state degeneracy, providing insights into black hole microstates.

Contribution

It introduces a non-extremal heterotic string black hole solution and links its entropy to microscopic string state counting, advancing understanding of black hole microstates.

Findings

Constructed a non-extremal four-dimensional heterotic string black hole.

Calculated the black hole entropy semiclassically.

Established the microscopic interpretation of entropy via string state degeneracy.

Abstract

We construct a four-dimensional BPS saturated heterotic string solution from the Taub-NUT solution. It is a non-extremal black hole solution since its Euler number is non-zero. We evaluate its black hole entropy semiclassically. We discuss the relation between the black hole entropy and the degeneracy of string states. The entropy of our string solution can be understood as the microscopic entropy which counts the elementary string states without any complications.