Black holes, information, and locality

TL;DR

This paper discusses the black hole information paradox, proposing that nonlocality in quantum gravity might resolve it, and emphasizes the need to understand the transition from nonlocal to local physics.

Contribution

It hypothesizes that non-perturbative quantum gravity dynamics is unitary yet nonlocal, offering a new perspective on the information paradox and the principle of locality.

Findings

Indicators suggest revising locality in quantum gravity.

Nonlocality may be essential for unitarity in black hole physics.

Understanding the correspondence limit is crucial for connecting nonlocal and local theories.

Abstract

Thirty years of a deepening information paradox suggest the need to revise our basic physical framework. Multiple indicators point toward reassessment of the principle of locality: lack of a precise definition in quantum gravity, behavior of high-energy scattering, hints from strings and AdS/CFT, conundrums of quantum cosmology, and finally lack of good alternative resolutions of the paradox. A plausible conjecture states that the non-perturbative dynamics of gravity is unitary but nonlocal. String theory may directly address these issues but so far important aspects remain elusive. If this viewpoint is correct, critical questions are to understand the "correspondence" limit where nonlocal physics reduces to local quantum field theory, and beyond, to unveil principles of an underlying nonlocal theory.