Revista Integración, temas de matemáticas.
Vol. 34 No. 1 (2016): Revista Integración
Research and Innovation Articles

On a finite moment perturbation of linear functionals and the inverse Szegö transformation

Edinson Fuentes
Universidad Pedagógica y Tecnológica de Colombia
Luis E. Garza
Universidad de Colima

Published 2016-05-06

Keywords

  • Orthogonal polynomials on the unit circle,
  • perturbation of moments,
  • inverse Szegö transformation

How to Cite

Fuentes, E., & Garza, L. E. (2016). On a finite moment perturbation of linear functionals and the inverse Szegö transformation. Revista Integración, Temas De matemáticas, 34(1), 39–58. https://doi.org/10.18273/revint.v34n1-2016003

Abstract

Given a sequence of moments $\{c_{n}\}_{n\in\ze}$ associated with an Hermitian linear functional $\mathcal{L}$ defined in the space of Laurent polynomials, we study a new functional $\mathcal{L}_{\Omega}$ which is a perturbation of $\mathcal{L}$ in such a way that a finite number of moments are perturbed. Necessary and sufficient conditions are given for the regularity of $\mathcal{L}_{\Omega}$, and a connection formula between the corresponding families of orthogonal polynomials is obtained. On the other hand, assuming $\mathcal{L}_{\Omega}$ is positive definite, the perturbation is analyzed through the inverse Szegö transformation.

To cite this article: E. Fuentes, L.E. Garza, On a finite moment perturbation of linear functionals and the inverse Szegö transformation, Rev. Integr. Temas Mat. 34 (2016), No. 1, 39–58.

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