Quantum strong cosmic censorship and black hole evaporation

TL;DR

This paper argues that semiclassical gravity and a new quantum strong cosmic censorship conjecture imply black hole evaporation does not lead to information loss, challenging the common folklore and suggesting unitarity is preserved.

Contribution

The paper introduces a rigorous quantum strong cosmic censorship conjecture that supports the preservation of unitarity in black hole evaporation.

Findings

Semiclassical gravity suggests formation of a final singularity rather than information loss.

A new quantum strong cosmic censorship conjecture is proposed and rigorously formulated.

Implication that unitarity is preserved in black hole evaporation processes.

Abstract

It is common folklore that semiclassical arguments suggest that in black hole evaporation an initially pure state can become mixed. This is known as the \emph{information loss puzzle} (or {\it paradox}). Here we argue that, if taken at face value, semiclassical gravity suggests the formation of a final singularity instead of information loss. A quantum strong cosmic censorship conjecture, for which we give a rigorous statement, supports this conclusion. Thus, there are no reasons to expect a failure of unitarity in black hole evaporation or for any quantum gravity theory that can `cure' singularities.