Alioscia Hamma, "To learn a mocking-black hole"

Wednesday 9 Oct 2024, 16:00 → 17:00 Europe/Rome

2G26

Does the information swallowed by a black hole vanish irretrievably, or could it possibly be recovered from the Hawking radiation emitted as the black hole gradually evaporates? Insights from black hole complementarity suggest that a black hole rapidly thermalizes quantum information, so that its internal dynamics can be represented as an instantaneous random unitary transformation. This recovery can happen if one knows the internal workings of a black hole, so the question is, can this structure be learned by observing the black hole long enough?

In this talk, we show some recent and surprising results: one can learn a quantum complex process like a black hole that cannot be efficiently simulated on a classical computer, and once one has learned it, one can simulate it efficiently. This is so surprising to sound impossible. I will argue that it is just short of impossible, that is, miraculous, and that what one learns efficiently are just salient features, while the noisy and difficult to simulate ones can be ditched away and turn out to be irrelevant.