Equations and Integrals of Motion in Discrete Integrable $A_{k-1}$ Algebra Models

Abstract

We study integrals of motion for Hirota bilinear difference equation that is satisfied by the eigenvalues of the transfer-matrix. The combinations of the eigenvalues of the transfer-matrix are found, which are integrals of motion for integrable discrete models for the $A_{k-1}$ algebra with zero and quasiperiodic boundary conditions. Discrete analogues of the equations of motion for the Bullough-Dodd model and non-Abelian generalization of Liouville model are obtained.