Worldsheet CFT2 and Celestial CFT2: An AdS3/CFT2 perspective

ADS seminar

Organizers：

数学物理团队

Speaker：

Nishant Gupta (National Institute of Science Education And Research)

Time：

Thur., 13:30 - 14:30, Oct. 16, 2025

Online：

ZOOM Meeting ID: 271 534 5558, Passcode: YMSC

Title:

Worldsheet CFT2 and Celestial CFT2: An AdS3/CFT2 perspective

Abstract:

Celestial conformal field theory in d dimensions is the putative dual of quantum gravity in asymptotically flat (d+2) dimensional space-time. In this talk, I will give an argument that a class of d-dimensional Celestial CFT can be engineered via AdS-CFT correspondence. The argument is based on the observation that zooming in near the boundary of (d+1) dimensional (Euclidean) AdS, the conformal isometry group of EAdS (SO(d + 2, 1)), contracts to the Poincaré group ISO(d + 1, 1). This suggests that the near-boundary scaling limit of a (d+1) dimensional theory of conformal gravity on EAdS should be dual to a boundary d-dimensional CFT with ISO(d + 1, 1) symmetry. This dual CFT, since the symmetries match, is an example of d-dimensional Celestial CFT. Similarly, for a (d+1) dimensional non-conformal theory of gravity on EAdS, the near-boundary scaling limit of such a theory is dual to a (boundary) Celestial CFT with only (SO(d+1, 1)) Lorentz invariance. Among other things, I will discuss the near-boundary scaling limit of the bosonic string theory on 3d Euclidean AdS. The EAdS part of the worldsheet theory in this limit describes a “long string” which wraps the (Euclidean) AdS boundary. We argue that the 2d space-time CFT describing the radial fluctuations of a long string is a Liouville CFT. According to our proposal, the dual CFT describing the long string sector is an example of a Celestial CFT with only (SO(3, 1)) Lorentz invariance.