Suneeta Vardarajan: The Generalized second law in crossed product constructions

Recent work uses the crossed product construction in von Neumann algebra to interpret black hole generalized entropy as the entropy of the algebra of observables of the black hole exterior. Further, there is also a proposal to assign an entropy to the algebra of observables in arbitrary subregions of spacetime. We review these works and show how they can be used to prove a local Generalized second law in crossed product constructions.