More quantum noise from wormholes

TL;DR

This work investigates how wormholes in dilaton gravity can encode the pseudorandom noise needed to preserve unitarity in black hole evaporation. Through both classical and quantum analyses in JT/dilaton gravity with matter, it shows that wormhole saddles reproduce ensemble-averaged off-diagonal correlations among Hawking-radiation states, linking Page-curve physics to a bulk description of noise. The results demonstrate that late-time correlators align with universal ensemble predictions, with kernels determined by thermal two-point functions, and clarify the role of replica wormholes in factorization debates. It also provides a concrete mechanism to stabilize wormholes in JT gravity by introducing a length potential, illuminating how geometry constrains the noise and its gravity dual.

Abstract

For black hole evaporation to be unitary, the naive density matrix of Hawking radiation needs to be corrected with a sprinkling of pseudorandom "noise." Using wormholes, semiclassical gravity appears to describe an averaged "true random" theory of this noise. We discuss the wormholes in dilaton gravity theories with matter. They are classical solutions that depend on a small amount of backreaction from matter fields, and they are closely related to the wormholes that give the Page curve.