Hawking Radiation from a Reisner-Nordstr\"om Domain Wall

TL;DR

This paper studies the time-dependent Hawking radiation emitted during the collapse of a Reisner-Nordstr"om domain wall, revealing charge effects on particle emission and temperature evolution consistent with charged black hole thermodynamics.

Contribution

It introduces a time-dependent analysis of Hawking radiation from charged collapsing domain walls using the functional Schr"odinger formalism, including charge effects and extremal cases.

Findings

Scalar particles unaffected by charge, behaving like uncharged case.

Charged particles show suppressed occupation when charge opposes the domain wall.

Temperature decreases over time in the extremal case, reaching zero at the horizon.

Abstract

We investigate the effect on the Hawking radiation given off during the time of collapse of a Reisner-Nordstr\"om domain wall. Using the functional Schr\"odinger formalism we are able to probe the time-dependent regime, which is out of the reach of the standard approximations like the Bogolyubov method. We calculate the occupation number of particles for a scalar field and complex scalar field. We demonstrate that the particles from the scalar field are unaffected by the charge of the Reisner-Nordstr\"om domain wall, as is expected since the scalar field doesn't carry any charge, which would couple to the charge of the Reisner-Nordstr\"om domain wall. Here the situation effectively reduces to the uncharged case, a spherically symmetric domain wall. To take the charge into account, we consider the complex scalar field which represents charged particles and anti-particles. Here investigate two different cases, first the non-extremal case and second the extremal case. In the non-extremal case we demonstrate that when the particle (anti-particle) carries charge opposite to that of the domain wall, the occupation number becomes suppressed during late times of the collapse. Therefore the dominate occupation number is when the particle (anti-particle) carries the same charge as the domain wall, as expected due to the Coulomb potential carried by the domain walls. In the extremal case we demonstrate that as time increases the temperature of the radiation decreases until when the domain wall reaches the horizon and the temperature then goes to zero. This is in agreement with the Hawking temperature for charged black holes.