Through December 5, 2023 3rd Floor Atrium
Page curves and replica wormholes from random Hamiltonians.
What is the underlying mechanism for the late-time purification of Hawking radiation from evaporating black holes? Which properties of gravity are important and which are not? In this talk, I will show how to capture both the non-unitary Hawking radiation entropy curve and density matrix-connecting contributions that restore unitarity in a toy quantum system with random dynamics. The motivation is to find the simplest dynamical model that captures this aspect of gravitational physics. In the model, the Hamiltonian obeys random matrix statistics within microcanonical windows, the entropy of the averaged state gives the non-unitary curve, the averaged entropy gives the unitary curve, and the difference comes from matrix index contractions in the Haar averaging that connect the density matrices in a replica wormhole-like manner.