Dynamical Horizons and Black Hole Soft Hair

TL;DR

This paper derives quasilocal charges related to black hole soft hair that suggest a mechanism for information to escape during black hole evaporation, potentially resolving the information loss paradox.

Contribution

It introduces a framework connecting Brown-York charges with supertranslation and superrotation hair, proposing a new scenario for black hole evaporation without event horizon formation.

Findings

Quasilocal charges match supertranslation and superrotation charges in large sphere limit.

A scenario where black holes evaporate without forming a true event horizon.

Information can escape via dynamical horizons, potentially preventing information loss.

Abstract

In the present work, quasilocal Brown-York charges are derived that coincide in the large sphere limit with the conserved supertranslation hair and superrotation charges introduced by Hawking, Perry and Strominger in [45, 46]. Given these charges, a general scenario is outlined in which a non-rotating black hole completely evaporates after its collapse due to particle creation effects, whereby a genuine one-way traversable event horizon is never formed, but merely a two-way traversable dynamical (resp. future trapping) horizon. The formation of such a dynamical horizon has the consequence, as is demonstrated, that quasilocal energy transported by the considered charges, and thus information, can continuously escape through the black hole horizon to infinity; a mechanism which, as is argued, could possibly prevent information loss once the black hole formation and evaporation process comes to an end.