Two-Dimensional Dilatonic Black Holes and Hawking Radiation

TL;DR

This paper investigates Hawking radiation from two-dimensional dilatonic black holes, considering their dynamical nature, revealing nonthermal radiation components and a nonzero temperature for extremal cases, with implications for black hole thermodynamics.

Contribution

It introduces a dynamical background approach to analyze Hawking radiation in 2D dilatonic black holes, highlighting nonthermal spectra and extremal black hole temperature.

Findings

Nonthermal component in Hawking radiation spectrum.

Nonzero temperature for extremal charged black holes.

Derivation of Bekenstein-Hawking area law for dynamical geometries.

Abstract

Hawking radiation emanating from two-dimensional charged and uncharged dilatonic black holes - dimensionally reduced from (2+1) spinning and spinless, respectively, BTZ black holes - is viewed as a tunnelling process. Two dimensional dilatonic black holes (AdS(2) included) are treated as dynamical backgrounds in contrast to the standard methodology where the background geometry is fixed when evaluating Hawking radiation. This modification to the geometry gives rise to a nonthermal part in the radiation spectrum. Nonzero temperature of the extremal two-dimensional charged black hole is found. The Bekenstein-Hawking area formula is easily derived for these dynamical geometries.