7 October 2021, 13:15 (EET), online seminar

• Andre Lima (Federal University of Espírito Santo, Brazil)
• Title: Twisted four-point functions in the D1-D5 CFT
• Abstract: The free (4,4) SCFT2 on the symmetric orbifold Sym(T^4)^N plays a prominent role in AdS3/CFT2. It gives the holographic description of geometries sourced by bound states of D1- and D5-branes compactified on the torus T^4 in Type IIB SUGRA, which become AdS3 x S^3 x T^4 in the near-brane decoupling limit. There is a dictionary between classes of states in the free orbifold CFT2 and classes of asymptotically AdS3 geometries carrying the same charges as the Strominger-Vafa D1-D5 black hole – a dictionary that underlies the microstate/fuzzball program. The free orbifold is a point in the moduli space of the strongly coupled holographic CFT, where the computation of renormalization-protected objects can be done exactly, to fill the dictionary entries. But even while the orbifold theory is free, its generic correlation functions are not trivial due to the non-Abelian boundary conditions associated with the symmetric group. Motivated by the holographic interpretation of the D1-D5 CFT, in this talk I will describe the computation of four-point functions of twisted fields, and discuss some results about the non-renormalization of Ramond ground states when the free orbifold is deformed by a particular marginal deformation.