Work

Firewalls from General Covariance

Year: 2025

Type: article

Abstract: I define "horizon normalcy" as the approximate validity of semiclassical gravity and effective field theory for the description of observers that approach or cross a black hole horizon. If black holes return information, then horizon normalcy must fail substantially, at least in some global states. It has been proposed that horizon normalcy persists, so long as the Hawking radiation remains in a computationally simple state. Here I argue that state-dependent horizon normalcy-independent of the underlying mechanism and independent of the class of radiation states asserted to guarantee normalcy-requires a breakdown of general covariance far from the black hole, or else horizon normalcy will depend on the infinite future of the exterior. This is because the radiation can be in different states at different events, all spacelike to the horizon crossing event whose normalcy is at stake. I discuss a related effect in AdS/CFT, and I argue that its resolution by timefolds is of no help here.

Source: Physical Review Letters

DOI: 10.1103/xl94-k5rj

Author: Raphael Bousso

Institution: University of California, Berkeley

Language: English

Topic: Black Holes and Theoretical Physics

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,750

Funder: U.S. Department of Energy