AdS_2 and quantum stability in the CGHS model

TL;DR

This paper constructs AdS_2 space within the CGHS model, showing quantum back reaction stabilizes black holes and prevents radiation, highlighting differences from flat black holes.

Contribution

It demonstrates quantum stability of AdS_2 black holes in the CGHS model and explains the absence of Hawking radiation.

Findings

AdS_2 space constructed in the CGHS model.

Quantum back reaction stabilizes AdS black holes.

No Hawking radiation in AdS_2 black holes.

Abstract

The two-dimensional anti-de Sitter space(AdS_2) is constructed in terms of the CGHS model. The geometric solutions are composed of the AdS vacuum and the AdS black hole which are locally equivalent but distinguishable by their mass. The infalling classical fields do not play any role but the quantum back reaction is crucial in the formation of the AdS vacuum and AdS black hole. In the presence of the AdS black hole, there does not exist any radiation, which is consistent with the constraint equations. Therefore the transition from the AdS black hole to the AdS vacuum is impossible, and they are quantum mechanically stable . We discuss the reason why the vanishing Hawking radiation appears in the AdS_2 black hole in contrast to asymptotically flat black holes.