A Black Hole Airy Tail: Part 2

Part 2 of the talk by Pratik Rath. In this talk, I will discuss a puzzle in JT (super)gravity coupled to matter, first observed by Lin-Maldacena-Rozenberg-Shan. The one-sided entropy of a two-sided black hole in the presence of many matter operator insertions becomes negative when naively computed using bulk techniques. This puzzle arises when computing annealed (instead of quenched) entropies. Using the semi-quenched entropy defined in Pratik's talk, I will explain how the positivity of entropy can be rescued. From the bulk perspective, both higher-genus topologies and wormhole effects are crucial, and the genus expansion of bulk matter diagrams must be re-summed. I will explain how this can be achieved for the LMRS setup and its generalization to non-supersymmetric JT gravity. From the matrix model perspective, the resolution relies on the statistics of eigenvalues near the edge, governed, in different regimes, by the Airy distribution or by eigenvalue instantons. Along the way, I will describe a new equivalence between many-point correlators in JT gravity with matter and pure JT gravity partition functions at low temperature, and explain its origin from a matrix model perspective.