Modifications of the Page Curve from correlations within Hawking radiation

TL;DR

This paper explores how quantum correlations within Hawking radiation can modify the Page curve, providing bounds on entanglement entropy changes and insights into resolving the black hole information paradox.

Contribution

It introduces a toy qubit model allowing larger quantum correlations and derives bounds on entanglement entropy, challenging previous assumptions about small corrections.

Findings

Quantum correlations can significantly alter the Page curve.

Bounds on entanglement entropy quantify the correction needed for unitarity.

Deviations from the expected Page curve are substantial under these correlations.

Abstract

We investigate quantum correlations between successive steps of black hole evaporation and investigate whether they might resolve the black hole information paradox. 'Small' corrections in various models were shown to be unable to restore unitarity. We study a toy qubit model of evaporation that allows small quantum correlations between successive steps and reaffirm previous results. Then, we relax the 'smallness' condition and find a nontrivial upper and lower bound on the entanglement entropy change during the evaporation process. This gives a quantitative measure of the size of the correction needed to restore unitarity. We find that these entanglement entropy bounds lead to a significant deviation from the expected Page curve.