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High Energy Theory Seminar

Friday, November 10, 2023
11:00am to 12:00pm
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Online and In-Person Event
Generalized entropy for general subregions in quantum gravity
Antony Speranza, University of Illinois Urbana-Champaign,

I will describe a construction of algebras of observables associated with local subregions in quantum gravity in the small G_N limit.  This algebra consists of operators dressed to a semiclassical observer degree of freedom which serves as an anchor defining the subregion.  I will argue that properly implementing the gravitational constraints on this algebra results in a type II von Neumann algebra, which possesses a well-defined notion of entropy.  Up to a state-independent constant, this entropy agrees with the UV-finite generalized entropy of the subregion, consisting of a Bekenstein-Hawking area term and a bulk entropy term.  This gives an algebraic explanation for the finiteness of the generalized entropy, and provides a number of tools for investigating aspects of semiclassical gravitational entropy, including the generalized second law, the quantum focusing conjecture, and the quantum extremal surface prescription in holography.

The talk is in 469 Lauritsen.

Contact [email protected] for Zoom information.