Dilaton driven Hawking radiation in AdS$_2$ black hole

TL;DR

This paper investigates how dilaton coupling affects Hawking radiation in AdS$_2$ black holes, revealing that coupling enables radiation where it was previously absent, and discusses implications for higher-dimensional black holes.

Contribution

It demonstrates that dilaton coupling induces Hawking radiation in AdS$_2$ black holes, contrasting with the non-radiative case without coupling.

Findings

Dilaton coupling enables Hawking radiation in AdS$_2$ black holes.

Without dilaton coupling, scalar fields are fully absorbed with no outgoing modes.

The study links dilaton dependence of Hawking radiation to three-dimensional black holes.

Abstract

A recent study shows that Hawking radiation of the massless scalar field does not appear on the two-dimensional AdS$_2$ black hole background. We study this issue by investigating absorption and reflection coefficients under dilaton coupling with the matter field. If the scalar field does not couple to the dilaton, then it is fully absorbed into the black hole without any outgoing mode. On the other hand, once it couples to the dilaton field, the outgoing mode of the massless scalar field exists and the nontrivial Hawking radiation is obtained. Finally, we comment on this dilaton dependence of Hawking radiation in connection with a three-dimensional black hole.