Black Hole Information Recovery in JT Gravity

TL;DR

This paper explores how information about objects falling into a black hole can be recovered from Hawking radiation in JT gravity, demonstrating quantum error correction, decoding complexity, and smooth horizon experience.

Contribution

It provides an exact analysis of information recovery, quantum error correction, and decoding complexity in JT gravity, refining the Hayden-Preskill scenario.

Findings

Information is redundantly encoded in Hawking radiation.

Decoding complexity is exponential in entropy measures.

Infalling observers experience a smooth horizon.

Abstract

We consider the issue of information recovery for an object carrying energy and entropy into a black hole using the generalized entropy formalism, in the context of JT gravity where the backreaction problem can be solved exactly. We verify the main aspects of the Hayden-Preskill scenario but with some refinements. We show that the information is encoded in the Hawking radiation in a redundant way, as expected for a quantum error correcting code. We show how quantum extremal surfaces associated to information recovery have the form of a python's lunch and thereby show that the complexity of decoding is exponential in a combination of the entropy shift of the black hole and the entropy of the object. We also show that an infalling observer must have a smooth experience at the horizon and we calculate their endurance proper time inside the black hole before they are radiated out.