SOME INTERESTING ASPECTS OF HAWKING RADIATION

Abstract

This paper is devoted to describe some important characteristics of Hawking radiation motivated by quantum field theory. We illustrate the Hawking radiation spectrum via tunneling phenomenon for axially symmetric rotating black holes having electric and magnetic charges. We evaluate tunneling probabilities of outgoing charged particles and also their corresponding Hawking temperature. Microscopic effects of black holes (BHs) are investigated properly by using the quantum theory in general relativity. Bekenstein 1 initiated the development of BH thermodynamics. Hawking 2 proposed that BHs are not purely black, they shine and emit radiation (energy/mass) named as Hawking radiation at finite Hawking temperature. This radiation is generated from gravitationalfield of BHs and explains the BH thermodynamical properties. Hawking radiation allows a BH to lose its mass and hence its evaporation. The final phase of BH evaporation is still unsatisfactory. The process in which particles have finite probability to cross the event horizon (not allowed classically) is called quantum tunneling. This mechanism is based on electron-positron pair production near the event horizon of a BH due to vacuum fluctuations, which requires an electric field. The positive-energy particles have the ability to penetrate energy barriers in the form of outgoing trajectories, while negative-energy particles tunnel inside and their corresponding actions become complex and real, respectively. Thus, the tunneling probability for the outgoing particle is governed by the imaginary part of the action which, in turn, is related to the Boltzmann factor for the emission at the Hawking temperature. There are various procedures 3 available to explore Hawking radiation. Some recent investigations 4 indicate keen interest in Hawking radiation as a phenomenon of quantum tunneling from different BHs. This study provides fermions tunneling spectrum for the general form of axially symmetric BH. The line element of axially symmetric rotating BH with G = c = 1 is 5