Hawking radiation as tunneling from the Kerr and Kerr-Newman black holes

TL;DR

This paper extends tunneling methods to Kerr and Kerr-Newman black holes, showing that considering conservation laws leads to non-thermal radiation spectra consistent with unitarity.

Contribution

It introduces a tunneling approach for rotating and charged black holes that accounts for conservation laws, revealing non-thermal spectra and entropy relations.

Findings

Tunneling rate relates to change in Bekenstein-Hawking entropy.

Emission spectrum deviates from pure thermal spectrum.

Results support unitarity in black hole radiation.

Abstract

Recent work, which treats the Hawking radiation as a semi-classical tunneling process at the horizon of the Schwarzschild and Reissner-Nordstrom spacetimes, indicates that the exact radiant spectrum is no longer pure thermal after considering the black hole background as dynamical and the conservation of energy. In this paper, we extend the method to investigate Hawking radiation as massless particles tunneling across the event horizon of the Kerr black hole and that of charged particles from the Kerr-Newman black hole by taking into account the energy conservation, the angular momentum conservation, and the electric charge conservation. Our results show that when self-gravitation is considered, the tunneling rate is related to the change of Bekenstein-Hawking entropy and the derived emission spectrum deviates from the pure thermal spectrum, but is consistent with an underlying unitary theory.