Discrete non-commutative hungry Toda lattice and its application in matrix computation
Zheng Wang, Shi-Hao Li, Kang-Ya Lu, Jian-Qing Sun
TL;DR
This work develops a pre-processing eigenvalue algorithm for block Hessenberg matrices by embedding the problem into a non-commutative integrable system built from matrix-valued $\theta$-deformed bi-orthogonal polynomials. By introducing adjacent polynomial families and discrete spectral transformations, the authors derive discrete non-commutative hungry Toda lattices and show how they reproduce recurrence relations and invariant eigenvalues under evolution. Finite truncation yields a generalized block qd-algorithm, with convergence guarantees under suitable spectral assumptions, and numerical experiments demonstrate accurate eigenvalue computation after preconditioning. The approach unifies matrix-valued orthogonal polynomials, quasi-determinants, and integrable lattice dynamics to inform robust numerical eigenvalue methods for structured matrices.
Abstract
In this paper, we plan to show an eigenvalue algorithm for block Hessenberg matrices by using the idea of non-commutative integrable systems and matrix-valued orthogonal polynomials. We introduce adjacent families of matrix-valued $θ$-deformed bi-orthogonal polynomials, and derive corresponding discrete non-commutative hungry Toda lattice from discrete spectral transformations for polynomials. It is shown that this discrete system can be used as a pre-precessing algorithm for block Hessenberg matrices. Besides, some convergence analysis and numerical examples of this algorithm are presented.
