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Physics Colloquium: "Black hole entropy from algebras and quantum error correction"

Event Type
Department of Physics
Loomis Lab 141 and via Zoom
wifi event
Feb 14, 2024   4:00 pm  
Tom Faulkner (UIUC)
Kelly H Darr
Originating Calendar
Physics - Colloquium

Recent advances in quantum gravity, using applications of effective field theory and the gravitational path integral, have improved our understanding of black hole entropy and the notion that a black hole, at least when viewed from the outside, is the macroscopic description of a chaotic quantum system with a Hilbert space of dimension exp(BH entropy). Notably these results are obtained with no knowledge of the exact microscopic/high energy completion of quantum gravity. I will review these results, emphasizing a new organizing principle that captures the black hole entropy as the entropy associated to a gravitational algebra. These gravitational algebras are classified using the mathematical theory of von Neumann algebras. I will then discuss a possible approach that embeds the effective field theory along with these gravitational algebras into a microscopic quantum theory. This embedding works like an approximate quantum error correcting code where effective field theory plays the role of the protected qubits, and the approximate nature is controlled by the small G_N limit. A precise realization of this setup is obtained using the AdS/CFT correspondence, a duality between certain quantum theories of gravity (string theories) and quantum field theory. 

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