Semiclassical charged black holes with a quantized massive scalar field

TL;DR

This paper investigates how a quantized massive scalar field affects the structure and properties of Reissner-Nordstrom black holes in a semiclassical framework, revealing that extreme black holes can surpass the charge-to-mass ratio of unity and analyzing temperature effects.

Contribution

It provides the first-order semiclassical perturbation analysis of charged black holes with a quantized scalar field using the DeWitt-Schwinger approximation, highlighting changes in charge-to-mass ratio and temperature.

Findings

Extreme black holes can have charge-to-mass ratios exceeding unity.

No zero-temperature solutions found for minimally or conformally coupled fields.

Perturbations influence black hole temperature and near-extreme states.

Abstract

Semiclassical perturbations to the Reissner-Nordstrom metric caused by the presence of a quantized massive scalar field with arbitrary curvature coupling are found to first order in \epsilon = \hbar/M^2. The DeWitt-Schwinger approximation is used to determine the vacuum stress-energy tensor of the massive scalar field. When the semiclassical perturbation are taken into account, we find extreme black holes will have a charge-to-mass ratio that exceeds unity, as measured at infinity. The effects of the perturbations on the black hole temperature (surface gravity) are studied in detail, with particular emphasis on near extreme ``bare'' states that might become precisely zero temperature ``dressed'' semiclassical black hole states. We find that for minimally or conformally coupled scalar fields there are no zero temperature solutions among the perturbed black holes.