Semiclassical Methods for Hawking Radiation from a Vaidya Black Hole

TL;DR

This paper derives a time-dependent Hawking temperature for Vaidya black holes using semiclassical tunneling methods, highlighting the dynamic nature of black hole evaporation and discussing the entropy implications.

Contribution

It extends semiclassical Hawking radiation analysis to Vaidya black holes, accounting for their time-dependent mass and temperature.

Findings

Hawking temperature is time-dependent for Vaidya black holes.

Radial null geodesic and complex paths methods yield consistent results.

Discussion on the possible form of black hole entropy.

Abstract

We derive the general form of Hawking temperature for Vaidya black hole in the tunneling pictures. This kind of black hole is regarded as the description of a more realistic one since it's time dependent decreasing mass due to the evaporation process. Clearly, the temperature would be time dependent as our findings. We use the semiclassical methods, namely radial null geodesic and complex paths methods. Both methods are found to give the same results. Then, we discuss the possible form of corresponding entropy.