On a finite moment perturbation of linear functionals and the inverse Szegö transformation
Published 2016-05-06
Keywords
- Orthogonal polynomials on the unit circle,
- perturbation of moments,
- inverse Szegö transformation
How to Cite
Copyright (c) 2016 Edinson Fuentes, Luis E. Garza
This work is licensed under a Creative Commons Attribution 4.0 International License.
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.
Downloads
References
- Bueno M.I. and Marcellán F., “Polynomial perturbations of bilinear functionals and Hessenberg matrices”, Linear Algebra Appl. 414 (2006), No.1, 64–83.
- Castillo K., Garza L.E. and Marcellán F., “Linear spectral transformations, Hessenberg matrices and orthogonal polynomials”, Rend. Circ. Mat. Palermo (2) Suppl. (2010), No.82, 3–26.
- Castillo K., Garza L.E. and Marcellán F., “Perturbations on the subdiagonals of Toeplitz matrices”, Linear Algebra Appl. 434 (2011), No. 6, 1563–1579.
- Castillo K. and Marcellán F., “Generators of rational spectral transformations for nontrivial C-functions”, Math. Comp. 82 (2013), No. 282,1057–1068.
- Fuentes E. and Garza L.E., “Analysis of perturbations of moments associated with orthogonality linear functionals through the Szeg´´o transformation”, Rev. Integr. Temas Mat.33 (2015), No. 1, 61–82.
- Garza L., Hernández J. and Marcellán F., “Spectral transformations of measures supported on the unit circle and the Szeg´´o transformation”, Numer. Algorithms. 49 (2008), No. 1-4,169–185.
- Grenander U. and Szeg´´o G., Toeplitz forms and their applications, Second ed., Chelsea Publishing Co., New York, 1984.
- Kreyszig E., Introductory functional analysis with applications, John Wiley & Sons Inc., New York, 1989.
- Peherstorfer F., “A special class of polynomials orthogonal on the circle including the associated polynomials”, Constr. Approx. 12 (1996), No. 2, 161–185.
- Simon B., Orthogonal polynomials on the unit circle. Part 1 and 2, American Mathematical Society Colloquium Publications 54, American Mathematical Society, Providence, RI, 2005.
- Szeg´´o G., Orthogonal polynomials, Fourth ed., American Mathematical Society Colloquium Publications 23, American Mathematical Society, Providence, RI, 1975.
- Zhedanov A., “Rational spectral transformations and orthogonal polynomials”, J. Comput.
- Appl. Math. 85 (1997), No. 1, 67–86.