Coarse graning pure states in AdS/CFT (Oct. 21, 2022)

  • Published: 2022-10-19

Time: Oct.21 (Friday) 13 pm - 15 pm.
Tencent Meeting: 795-5992-5570


Speaker: Tengzhou Lai (UCAS)



We construct new Euclidean wormhole solutions in AdSd+1 and discuss their role in UV-complete theories, without ensemble averaging. The geometries are interpreted as overlaps of GHZ-like entangled states, which arise naturally from coarse graining the density matrix of a pure state in the dual CFT. In several examples, including thin-shell collapsing black holes and pure black holes with an end-of-the-world brane behind the horizon, the coarse-graining map is found explicitly in CFT terms, and used to define a coarse-grained entropy that is equal to one quarter the area of a time-symmetric apparent horizon. Wormholes are used to derive the coarse-graining map and to study statistical properties of the quantum state. This reproduces aspects of the West Coast model of 2D gravity and the large-c ensemble of 3D gravity, including a Page curve, in a higherdimensional context with generic matter fields.This talk is mainly based on the paper 2206.03414 and if you are interested in the details of EOW brane, 1810.10601 is also recommended.