A generalization of Laurent biorthogonal polynomials and related integrable lattices

Abstract

This paper is concerned about certain generalization of Laurent biorthogonal polynomials together with the corresponding related integrable lattices. On one hand, a generalization for Laurent biorthogonal polynomials is proposed and its recurrence relation and Christoffel transformation are derived. On the other hand, it turns out the compatibility condition between the recurrence relation and the Christoffel transformation for the generalized Laurent biorthogonal polynomials yields an extension of the fully discrete relativistic Toda lattice. And also, it is shown that isospectral deformations of the generalized Laurent biorthogonal polynomials lead to two different generalizations of the continuous-time relativistic Toda lattice, one of which can reduce to the Narita–Itoh–Bogoyavlensky lattice.