Backreaction Effects in the Two-Dimensional Dilaton Gravity

TL;DR

This paper investigates backreaction effects in two-dimensional dilaton gravity with an added $R^2$ term, revealing static black hole solutions that suggest non-thermal evolution without complete evaporation.

Contribution

It introduces static black hole solutions in modified 2D dilaton gravity incorporating an $R^2$ term from one-loop scalar field effects, highlighting backreaction and non-thermal evolution.

Findings

Backreaction effects can be modeled with an $R^2$ term.

Black hole evolution via non-thermal signals is possible.

Black holes do not fully evaporate, with Hawking radiation remaining dominant.

Abstract

In this work we find static black hole solutions in the context of the two-dimensional dilaton gravity, which is modified by the addition of an $R^2$ term. This term arises from the one-loop effective action of a massive scalar field in its large mass expansion. The basic feature of this term is that it does not contribute to the Hawking radiation of the classical black hole backgrounds of the model. From this point of view a class of the solutions derived are interpreted as describing backreaction effects. In particular it is argued that evolution of a black hole via non-thermal signals is possible. Nevertheless this evolution seems to be 'soft', in the sense that it does not lead to the evaporation of a black hole, leaving the Hawking radiation as the dominant mechanism for this process.