Hawking radiation from the quantum Lemaitre-Tolman-Bondi model

TL;DR

This paper derives Hawking radiation from the quantum Lemaître-Tolman-Bondi model using exact solutions of the Wheeler-DeWitt equation, revealing modifications to the blackbody spectrum due to greybody factors.

Contribution

It provides the first derivation of Hawking radiation in non-marginally bound LTB models using exact quantum solutions, including corrections beyond the near horizon approximation.

Findings

Hawking radiation maintains an approximate Planck spectrum near the horizon.

Corrections introduce greybody factors that modify the blackbody spectrum.

Exact solutions enable reliable computation of Bogoliubov coefficient corrections.

Abstract

In an earlier paper, we obtained exact solutions of the Wheeler-DeWitt equation for the Lemaitre-Tolman-Bondi (LTB) model of gravitational collapse, employing a lattice regularization. In this paper, we derive Hawking radiation in non-marginally bound models from our exact solutions. We show that a non-vanishing energy function does not spoil the (approximate) Planck spectrum near the horizon. We can also reliably compute corrections to the Bogoliubov coefficient because our solutions are exact. The corrections are obtained by going beyond the near horizon region and are shown to introduce additional greybody factors, which modify the black body spectrum of radiation from the black hole.