Kadanoff Seminar: Generalized entropy for general subregions in quantum gravity. - Antony Speranza, UIUC

1:30 pm MCP 201

Generalized entropy for general subregions in quantum gravity.

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. 

Event Type


Nov 6