Hawking Radiation for Non-minimally Coupled Matter from Generalized 2D Black Hole Models

TL;DR

This paper investigates Hawking radiation in generalized 2D black hole models with non-minimally coupled scalar matter, revealing a negative flux in certain models and correcting previous results.

Contribution

It extends and corrects prior work on Hawking radiation in dilaton models with non-minimal coupling, analyzing global structure and flux ambiguities.

Findings

Negative Hawking flux at infinity in SSG models

Correction of previous results on Hawking radiation

Discussion of ambiguities in non-minimal coupling models

Abstract

It is well known that spherically symmetric reduction of General Relativity (SSG) leads to non-minimally coupled scalar matter. We generalize (and correct) recent results to Hawking radiation for a class of dilaton models which share with the Schwarzschild black hole non-minimal coupling of scalar fields and the basic global structure. An inherent ambiguity of such models (if they differ from SSG) is discussed. However, for SSG we obtain the rather disquieting result of a negative Hawking flux at infinity, if the usual recipe for such calculations is applied.