One-shot decoupling and Page curves from a dynamical model for black hole evaporation

TL;DR

This paper models black hole evaporation using a trilinear Hamiltonian and demonstrates that quantum information is perfectly transferred to radiation, reproducing Page curves and supporting the role of decoupling in resolving the information paradox.

Contribution

It provides a numerical demonstration that decoupling is exact in a black hole model, linking quantum information transfer to Page curve emergence.

Findings

Decoupling is exact in the continuous limit of the model.

Page's entropy profile emerges naturally from the dynamics.

Information transfer is robust across multi-linear Hamiltonians.

Abstract

One-shot decoupling is a powerful primitive in quantum information theory and was hypothesized to play a role in the black hole information paradox. We study black hole dynamics modeled by a trilinear Hamiltonian whose semiclassical limit gives rise to Hawking radiation. An explicit numerical calculation of the discretized path integral of the S-matrix shows that decoupling is exact in the continuous limit, implying that quantum information is perfectly transferred from the black hole to radiation. A striking consequence of decoupling is the emergence of an output radiation entropy profile that follows Page's prediction. We argue that information transfer and the emergence of Page curves is a robust feature of any multi-linear interaction Hamiltonian with a bounded spectrum.