Hawking radiation in GHS blackhole, Effective action and Covariant Boundary condition

TL;DR

This paper derives Hawking radiation from GHS blackholes using anomalous effective action and covariant boundary conditions, establishing a link between anomalous and normal energy-momentum tensors.

Contribution

It introduces a method to compute Hawking radiation for GHS blackholes via covariant boundary conditions and effective action, extending previous approaches to more general blackholes.

Findings

Hawking radiation can be obtained from GHS blackholes using covariant boundary conditions.

The connection between anomalous and normal energy-momentum tensors is established.

The method applies to a broad class of spherically symmetric blackholes.

Abstract

We exploit the expression for the anomalous (chiral) effective action to obtain the Hawking radiation from the GHS (stringy) blackhole falling in the class of the most general spherically symmetric blackholes $(\sqrt{-g}\neq1)$, using only covariant boundary condition at the event horizon. The connection between the anomalous and the normal energy-momentum tensors is also established from the effective action approach.