Analogue Hawking Radiation from Astrophysical Black Hole Accretion

TL;DR

This paper demonstrates that spherical accretion onto astrophysical black holes can serve as a natural analogue system for studying Hawking radiation, providing exact analytical methods for calculating analogue temperature and surface gravity.

Contribution

It introduces the first exact analytical scheme for calculating analogue Hawking temperature in astrophysical black hole accretion, linking accretion theory with analogue Hawking radiation.

Findings

Analogue Hawking temperature can dominate over actual Hawking temperature in astrophysical contexts.

The analytical scheme applies to black holes of any mass.

Possibility of analogue white hole formation around black holes.

Abstract

We show that spherical accretion onto astrophysical black holes can be considered as a natural example of analogue system. We provide, for the first time, an exact analytical scheme for calculating the analogue Hawking temperature and surface gravity for general relativistic accretion onto astrophysical black holes. Our calculation may bridge the gap between the theory of transonic astrophysical accretion and the theory of analogue Hawking radiation. We show that the domination of the analogue Hawking temperature over the actual Hawking temperature may be a real astrophysical phenomena. We also discuss the possibilities of the emergence of analogue white holes around astrophysical black holes. Our calculation is general enough to accommodate accreting black holes with any mass.