How Fast Does Information Leak out from a Black Hole?

TL;DR

This paper investigates the rate at which information can escape from a black hole through Hawking radiation, suggesting that quantum effects may allow information to gradually leak out over the black hole's lifetime.

Contribution

It provides an upper bound on the information outflow rate from black holes, challenging the notion of complete information loss.

Findings

The radiation departs from a perfect blackbody spectrum.

The maximum information leakage rate exceeds the black hole's entropy decrease rate.

Quantum effects could enable gradual information recovery from black holes.

Abstract

Hawking's radiance, even as computed without account of backreaction, departs from blackbody form due to the mode dependence of the barrier penetration factor. Thus the radiation is not the maximal entropy radiation for given energy. By comparing estimates of the actual entropy emission rate with the maximal entropy rate for the given power, and using standard ideas from communication theory, we set an upper bound on the permitted information outflow rate. This is several times the rates of black hole entropy decrease or radiation entropy production. Thus, if subtle quantum effects not heretofore accounted for code information in the radiance, the information that was thought to be irreparably lost down the black hole may gradually leak back out from the black hole environs over the full duration of the hole's evaporation.