Validity of the Semiclassical Approximation and Back=reaction

TL;DR

This paper demonstrates that the semiclassical approximation remains valid in weak curvature regions of two-dimensional evaporating black holes when back-reaction effects are properly included, ensuring accurate modeling of black hole evaporation.

Contribution

It provides a rigorous validation of the semiclassical approximation in the context of evaporating black holes by incorporating back-reaction effects.

Findings

Semiclassical approximation is valid in weak curvature regions.

Back-reaction effects are crucial for the validity of the approximation.

The approach applies to the horizon region of evaporating black holes.

Abstract

Studying two-dimensional evaporating dilatonic black holes, we show that the semiclassical approximation, based on the background field approach, is valid everywhere in regions of weak curvature (including the horizon), as long as one takes into account the effects of back-reaction of the Hawking radiation on the background geometry.