activity
20242026
collaborators

10 papers

math.CV2026

Zeros of Laurent multiple orthogonal polynomials on the unit circle

Rostyslav Kozhan, Marcus Vaktnäs

We investigate two distinct formulations of Laurent multiple orthogonal polynomials on the unit circle, introduced in arXiv:2410.12094 and arXiv:2601.04783 respectively. For the fi…

math.CA2026

Determinantal Formulas for Rational Perturbations of Multiple Orthogonality Measures

Rostyslav Kozhan, Marcus Vaktnäs

Given multiple orthogonal polynomials on the real line with respect to a system , we investigate multiple orthogonal polynomials associated with any rat…

math.CA2026

Szegő Mapping and Hermite--Padé Polynomials for Multiple Orthogonality on the Unit Circle

Rostyslav Kozhan, Marcus Vaktnäs

We investigate generalized Laurent multiple orthogonal polynomials on the unit circle satisfying simultaneous orthogonality conditions with respect to probability measures or l…

math.CA2026

Angelesco and AT systems on the Unit Circle

Rostyslav Kozhan, Marcus Vaktnäs

We introduce the concept of Laurent multiple orthogonality on the unit circle and define Angelesco and AT systems in this setting. Using a generalized Andreief identity, we establi…

math.CA2025

Ratio asymptotics and zero density for orthogonal polynomials with varying Verblunsky coefficients

Rostyslav Kozhan, František Štampach

We study asymptotic behavior of orthogonal polynomials on the unit circle with varying Verblunsky coefficients when the ratio converges as . First, w…

math.CA2025

Christoffel Transform and Multiple Orthogonal Polynomials

Rostyslav Kozhan, Marcus Vaktnäs

We investigate multiple orthogonal polynomials associated with the system of measures obtained by applying a Christoffel transform to each of the orthogonality measures. We present…