Quantum Radiation Properties of Dirac Particles in General Nonstationary Black Holes

TL;DR

This paper investigates the quantum radiation properties of Dirac particles in dynamic black holes, revealing that their temperature, horizon shape, and radiation spectrum depend on time and angles, with new effects and relationships identified.

Contribution

It introduces a general expression for the extra coupling effect in Dirac particle radiation and uncovers a novel relationship between thermal and non-thermal radiation in nonstationary black holes.

Findings

Temperature and horizon shape depend on time and angles.

New coupling effect in Dirac particle radiation spectrum.

Chemical potential equals highest negative energy state in non-thermal radiation.

Abstract

Quantum radiation properties of Dirac particles in general nonstationary black holes in the general case is investigated by both using the method of generalized tortoise coordinate transformation and considering the asymptotic behaviors of both the first and second order forms of Dirac equations near the event horizon. It is generally shown that the temperature and shape of event horizon of this kind of black holes depend on both the time and different angles. Further, we give a general expression of the new extra coupling effect in thermal radiation spectrum of Dirac particles which is missing in that of scalar particles. Also, we reveal a relationship that is ignored before between thermal radiation and non-thermal radiation in the case of scalar particles, which is that the chemical potential in thermal radiation spectrum is equal to the highest energy of the negative energy state of scalar particles in non-thermal radiation for general nonstationary black holes.