English

Exact solution for a matrix dynamical system with usual and Hadamard inverses

Exactly Solvable and Integrable Systems 2007-05-23 v2

Abstract

Let A be an n*n matrix with entries a_ij in the field C. Consider the following two involutive operations on such matrices: the matrix inversion I: A -> A^-1 and the element-by-element (or Hadamard) inversion J: a_ij -> a_ij^-1. We study the algebraic dynamical system generated by iterations of the product JI. In the case n=3, we give the full explicit solution for this system in terms of the initial matrix A. In the case n=4, we provide an explicit ansatz in terms of theta-functions which is full in the sense that it works for a Zariski open set of initial matrices. This ansatz also generalizes for higher n where it gives partial solutions.

Cite

@article{arxiv.nlin/0303007,
  title  = {Exact solution for a matrix dynamical system with usual and Hadamard inverses},
  author = {I. G. Korepanov},
  journal= {arXiv preprint arXiv:nlin/0303007},
  year   = {2007}
}

Comments

10 pages; a few small improvements in this revised version

R2 v1 2026-07-22T18:10:40.454Z