Nonviolent nonlocality

TL;DR

This paper explores a gentler form of nonlocal information transfer in black holes, proposing models that could reconcile unitarity with observable physics, and suggests potential experimental signatures of such mechanisms.

Contribution

It introduces simplified models of nonlocal information transfer in black holes within a tensor network framework, aiming to resolve conflicts between unitarity and semiclassical physics.

Findings

Black holes may transfer information via soft modes in their atmosphere.

Infalling observers could detect deviations from Hawking radiation predictions.

Black holes could decay faster under certain nonlocal transfer models.

Abstract

If quantum mechanics governs nature, black holes must evolve unitarily, providing a powerful constraint on the dynamics of quantum gravity. Such evolution apparently must in particular be nonlocal, when described from the usual semiclassical geometric picture, in order to transfer quantum information into the outgoing state. While such transfer from a disintegrating black hole has the dangerous potential to be violent to generic infalling observers, this paper proposes the existence of a more innocuous form of information transfer, to relatively soft modes in the black hole atmosphere. Simplified models for such nonlocal transfer are described and parameterized, within a possibly more basic framework of a Hilbert tensor network. Sufficiently sensitive measurements by infalling observers may detect departures from Hawking's predictions, and in generic models black holes decay more rapidly. Constraints of consistency -- internally and with known and expected features of physics -- restrict the form of information transfer, and should provide important guides to discovery of the principles and mechanisms of the more fundamental nonlocal mechanics.