Seminar----Institute of Theoretical Physics，Chinese Academy of Sciences

Institute of Theoretical Physics
Chinese Academy of Sciences
Key Laboratory of Theoretical Physics
Seminar
Title 题目	Holographic description of entanglement entropy and conformal block in $AdS_3/CFT_2$
Speaker 报告人	Jieqiang Wu(吴杰强)
Affiliation 所在单位	Peking University
Date 日期	3:30pm, Wednesday, Apr. 26, 2017
Venue 地点	Conference Hall 322, ITP
Abstract 摘要	$AdS_3/CFT_2$ is a good arena to study holography. In this work, we focus on two dimensional conformal field theory. In semi-classical limit, the conformal block can be studied by solving a monodromy problem. We extend this technic to more general case to study entanglement entropy and heavy operator conformal block. For entanglement entropy, we use the monodromy trick to study the entanglement for a general class of states. We found the final result is consistent with Ryu-Takayanagi formula. Actually, in gravity side, if we use Chern-Simons form, there is direct correspondence with the field theory calculation. For the heavy operator conformal block, we expect it should dual to an on-shell action in gravity with conical defects. In gravity side, if we take a variation with respect to the conical angle, we get the length of conical defect. In field theory side, it implies by taking a variation with conformal dimension, we get a quantity which dual to length of conical defect. We prove this relation in CFT_2. It is a strong support for the holographic description of conformal block.
Contact person	Gang Yang