Kerr/CFT Correspondence in the Low Energy Limit of Heterotic String Theory

TL;DR

This paper explores the Kerr/CFT correspondence within heterotic string theory by analyzing extremal Kerr-Sen black holes, deriving conserved charges, and confirming the conjecture that non-gravitational fields do not contribute to the central charge, matching microscopic and macroscopic entropies.

Contribution

It extends the Kerr/CFT correspondence to include heterotic string theory with antisymmetric tensor fields, confirming the vanishing of non-gravitational central charges.

Findings

Confirmed the vanishing of non-gravitational field central charges.

Derived conserved charges for extremal Kerr-Sen black holes.

Matched microscopic entropy with Bekenstein-Hawking entropy.

Abstract

We investigate the recently proposed Kerr/CFT correspondence in the context of heterotic string theory. The Kerr/CFT correspondence states that the near-horizon states of an extremal four (or higher) dimensional black hole could be identified with a certain chiral conformal field theory under the conjecture that the central charges from the non-gravitational fields vanish. The corresponding Virasoro algebra is generated by a class of diffeomorphisms which preserves the appropriate boundary conditions on the near-horizon geometry. To understand the chiral conformal field theory, we consider the class of extremal Kerr-Sen black hole (that contains three non-gravitational fields) as a class of solutions in the low energy limit (effective field theory) of heterotic string theory. We derive the expression of the conserved charges for the extremal Kerr-Sen solutions that contain dilaton, abelian gauge filed and antisymmetric tensor filed. We confirm and extend the validity of the conjecture (that the central charges from the non-gravitational fields vanish) for theories including antisymmetric tensor fields. We combine the calculated central charges with the expected form of the temperature using the Cardy formula to obtain the entropy of the extremal black hole microscopically; in agreement with the macroscopic Bekenstein-Hawking entropy of the extremal black hole.