Non-strictly black body spectrum from the tunnelling mechanism

TL;DR

This paper modifies the tunnelling mechanism approach to derive a non-strictly black body spectrum for Hawking radiation, reconciling previous conflicting results and discussing implications for the black hole information paradox.

Contribution

It introduces an effective state and modifies the Banerjee-Majhi analysis to obtain a non-strictly thermal spectrum consistent with Parikh and Wilczek's findings.

Findings

Derived a non-strictly black body spectrum from tunnelling

Reconciled previous conflicting results on black hole radiation spectrum

Discussed implications for the black hole information puzzle

Abstract

A modern and largely used approach to obtain Hawking radiation is the tunnelling mechanism. However, in various papers in the literature, the analysis concerned almost only to obtain the Hawking temperature through a comparison of the probability of emission of an outgoing particle with the Boltzmann factor. In a interesting and well written paper, Banerjee and Majhi improved the approach, by explicitly finding a black body spectrum associated with black holes. On the other hand, this result, which has been obtained by using a reformulation of the tunnelling mechanism, is in contrast which the remarkable result by Parikh and Wilczek, that, indeed, found a probability of emission which is compatible with a non-strictly thermal spectrum. By using our recent introduction of an effective state for a black hole, here we solve such a contradiction, through a slight modification of the analysis by Banerjee and Majhi. The final result will be a non-strictly black body spectrum from the tunnelling mechanism. We also show that, for an effective temperature, we can write the corresponding effective metric by Hawking's periodicity arguments. Potential important implications for the black hole information puzzle are also discussed