A discretization of the Schur flow and its applications

Yoshimasa Nakamura

Abstract: The Schur flow is a deformation equation of the Schur parameter which is induced by a linear evolution of measures for orthogonal polynomials on the unit circle. The Schur flow is an integrable system admitting a tau-function solution as well as a Lax representation. In this talk I first give an integrable time discretization of the Schur flow where the tau-function plays a central role. As applications of the discrete Schur flow two algorithms are designed. One is a continued fraction expansion algorithm of given power series. The other is an algorithm for computing zeros of given polynomials.