The TT* deformation at large central charge

Understand

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.