Tunneling across dilaton coupled black holes in anti de Sitter spacetime

TL;DR

This paper investigates Hawking radiation from dilaton-coupled black holes in anti-de Sitter spacetime, comparing different methods and analyzing how the dilaton coupling affects temperature and flux.

Contribution

It provides a detailed analysis of Hawking radiation in dilaton black holes, establishing equivalence between tunneling and anomaly methods for flux calculation.

Findings

Hawking flux increases with dilaton coupling parameter

Hawking temperature depends on dilaton coupling and extremality conditions

Different approaches to Hawking radiation yield consistent results

Abstract

Considering generalised action for dilaton coupled Maxwell-Einstein theory in four dimensions, Gao and Zhang obtained black holes solutions for asymptotically anti de Sitter (Ads) and de Sitter (ds) spacetimes. We study the Hawking radiation in Parikh-Wilczek's tunneling formalism as well as using Bogoliubov transformations. We compare the expression of the Hawking temperature obtained from these two different approaches. Stability and the extremality conditions for such black holes are discussed. The exact dependences of the Hawking temperature and flux on the dilaton coupling parameter are determined. It is shown that the Hawking flux increases with the dilaton coupling parameter. Finally we show that the expression for the Hawking flux obtained using Bogoliubov transformation matches exactly with flux calculated via chiral gauge and gravitational anomalies. This establishes a correspondence among all these different approaches of estimating Hawking radiation from these class of black holes.