# Unitarity in Reissner-Nordstr\"{o}m background: striding away from information loss

## TL;DR

This paper demonstrates that radiation from a collapsing charged shell forming a Reissner-Nordström black hole evolves unitarily, challenging the notion of information loss in such spacetimes by using a Wheeler-deWitt formalism.

## Contribution

It provides an analytical proof of unitarity in the radiation process of charged black holes within a non-globally hyperbolic background, employing the Wheeler-deWitt approach.

## Key findings

- Trace of the squared density matrix equals one
- Probability conservation is confirmed for the wave function
- Radiation evolution is unitary in the RN background

## Abstract

We have shown analytically that radiation from a collapsing shell which leads to a charged black hole, whose exterior is described by the RN (Reissner-Nordstr\"om) metric (and hence the background spacetime is non-globally hyperbolic), is processed with a unitary evolution. For the analysis, we have used the Wheeler-deWitt formalism which in turn gave rise to a Schr\"{o}dinger-like wave equation. We showed the existence of unitarity by proving that the trace of the squared density matrix of the outgoing radiation, from a quantized massless scalar field, is unity and that the conservation of probability holds for the wave function of the system.