The TT* deformation at large central charge

TL;DR

This paper analyzes the TT* deformation of 2D quantum field theories at large central charge, revealing exact computability of correlation functions and the disappearance of non-local effects in a specific limit.

Contribution

It introduces a 't Hooft-like limit for TT* deformations, showing that correlation functions become exactly computable and local, with explicit results for deformed three-point functions.

Findings

Correlation functions are exactly computable in the limit.

Non-local effects vanish at large central charge.

Explicit three-point functions of the energy-momentum tensor are derived.

Abstract

We study Zamolodchikov's TT* deformation of two dimensional quantum field theories in a 't Hooft-like limit, in which we scale the number of degrees of freedom c to infinity and the deformation parameter t to zero, keeping their product t*c fixed (more precisely, we keep energies and distances fixed in units of t*c). In this limit the Hagedorn temperature remains fixed, but other non-local aspects of the theory disappear. We show that in this limit correlation functions may be computed exactly, and they are local in space and polynomials in t. We compute explicitly the deformed three-point functions of the energy-momentum tensor for a TT*-deformed conformal field theory.