Quasi-particle production during gravitational collapse of a Reissner–Nordström–AdS domain wall

Abstract

In this paper, we investigate the gravitational collapse of a Reissner–Nordström–AdS domain wall for both a nonextremal and overcharged collapse. During the collapse, we investigate the quasi-particle production that arises due to the time-dependent metric by coupling a complex scalar field to the background of the collapsing domain wall. The analysis is done by making use of the Ermakov equations which lead to an exact solution for the auxiliary function found in the Milne–Pinney equation. In the nonextremal case, we find that assuming the domain wall is positively charged, where the negatively charged particle production is suppressed compared to the positively charged particles due to the Coulomb attraction and repulsion of the particles with the domain wall itself. The induced quasi-particles approach thermality as time goes to infinity in the IR region of the spectrum, however the UV region of the spectrum remains nonthermal for all time. In the overcharged case, the domain wall oscillates about a radius outside of the naked singularity, abiding by the cosmic censorship conjecture, due to the competition between the Coulomb repulsion and the gravitational attraction. Due to the periodic behavior of the collapsing domain wall, the quasi-particle production acquires a generalized Berry Phase, which is a real and measurable phase. The generalized Berry phase leads to a suppression of the UV region of the spectrum.