Flow Equations for Generalized TT[over ¯] Deformations.

We consider the most general set of integrable deformations extending the TT[over ¯] deformation of two-dimensional relativistic QFTs. They are CDD deformations of the theory's factorized S matrix related to the higher-spin conserved charges. Using a mirror version of the generalized Gibbs ensemble, we write down the finite-volume expectation value of the higher-spin charges, and derive a generalized flow equation that every charge must obey under a generalized TT[over ¯] deformation.

The Bethe ansatz and the Tzitzéica-Bullough-Dodd equation.

The theory of classically integrable nonlinear wave equations and the Bethe ansatz systems describing massive quantum field theories defined on an infinite cylinder are related by an important mathematical correspondence that still lacks a satisfactory physical interpretation. In this paper, we shall extend this link to the case of the classical and quantum versions of the Tzitzéica-Bullough-Dodd model.