How fast can a black hole release its information?

TL;DR

This paper estimates the timescale for information to escape from a black hole, suggesting that quantum effects allow information to be released much faster than previously thought, via the relaxation into fuzzball states.

Contribution

It provides a simple estimate showing that quantum spreading enables information release from black holes on timescales shorter than Hawking evaporation.

Findings

Spreading time is much shorter than Hawking evaporation time.

Information can escape through relaxation into fuzzball states.

Quantum effects significantly alter classical black hole evolution.

Abstract

When a shell collapses through its horizon, semiclassical physics suggests that information cannot escape from this horizon. One might hope that nonperturbative quantum gravity effects will change this situation and avoid the `information paradox'. We note that string theory has provided a set of states over which the wavefunction of the shell can spread, and that the number of these states is large enough that such a spreading would significantly modify the classically expected evolution. In this article we perform a simple estimate of the spreading time, showing that it is much shorter than the Hawking evaporation time for the hole. Thus information can emerge from the hole through the relaxation of the shell state into a linear combination of fuzzballs.