## Abstract This paper contains further steps towards a Szegö theory for orthogonal rational matrix‐valued functions on the unit circle 𝕋. It continues the investigations started in [18]–[20]. Hereby we are guided by former work of Bultheel, González–Vera, Hendriksen, and Njåstad on scalar orthogon
Orthogonal rational matrix-valued functions on the unit circle
✍ Scribed by Bernd Fritzsche; Bernd Kirstein; Andreas Lasarow
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 391 KB
- Volume
- 278
- Category
- Article
- ISSN
- 0025-584X
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✦ Synopsis
Abstract
This paper contains first steps towards a Szegö theory of orthogonal rational matrix‐valued functions on the unit circle 𝕋. Hereby we are guided by former work of Bultheel, González‐Vera, Hendriksen, and Njåstad on scalar orthogonal rational functions on the one side and by investigations of Delsarte, Genin, and Kamp on orthogonal matrix polynomials on the other side. An essential characteristic of our matricial orthogonalization procedure is marked by an intensive interplay between left and right matrix‐valued inner products generated by a nonnegative Hermitian Borel measure on the unit circle. The main feature of our approach is the distinguished role of Christoffel‐Darboux formulas. We consider pairs of rational matrix‐valued functions linked via Christoffel‐Darboux type relations as an own subject. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
📜 SIMILAR VOLUMES
The set P of all probability measures s on the unit circle T splits into three disjoint subsets depending on properties of the derived set of {|j n | 2 ds} n \ 0 , denoted by Lim(s). Here {j n } n \ 0 are orthogonal polynomials in L 2 (ds). The first subset is the set of Rakhmanov measures, i.e., of