2021/12/23 by Edward Witten · 1 voice · 3 citations
Physics and Astronomy · #hep-th #gr-qc
paper · pdf · doi:10.1007/jhep10(2022)008
arxiv published 2021/12/23 · arxiv updated 2022/09/19
Recently Leutheusser and Liu [1,2] identified an emergent algebra of Type III1 in the operator algebra of \mathcal N=4 super Yang-Mills theory for large N. Here we describe some 1/N corrections to this picture and show that the emergent Type III1 algebra becomes an algebra of Type II_∞. The Type II_∞ algebra is the crossed product of the Type III1 algebra by its modular automorphism group. In the context of the emergent Type II_∞ algebra, the entropy of a black hole state is well-defined up to an additive constant, independent of the state. This is somewhat analogous to entropy in classical physics.