Characteristic Function, Schur Parameters and Pseudocontinuation of Schur functions

التفاصيل البيبلوغرافية
العنوان: Characteristic Function, Schur Parameters and Pseudocontinuation of Schur functions
المؤلفون: Dubovoy, Vladimir K., Fritzsche, Bernd, Kirstein, Bernd, Mädler, Conrad, Müller, Karsten
سنة النشر: 2023
المجموعة: Mathematics
مصطلحات موضوعية: Mathematics - Complex Variables, Mathematics - Analysis of PDEs, Mathematics - Classical Analysis and ODEs, 30J10 (Primary) 47A48, 47A45, 30E05, 47A57 (Secondary)
الوصف: In [19] there is an approach to the investigation of the pseudocontinuability of Schur functions in terms of Schur parameters. In particular, there was obtained a criterion for the pseudocontinuability of Schur functions and the Schur parameters of rational Schur functions were described. This approach is based on the description in terms of the Schur parameters of the relative position of the largest shift and the largest coshift in a completely nonunitary contraction. It should be mentioned that these results received a further development in [8, 21-24]. This paper is aimed to give a survey about essential results on this direction. The main object in the approach is based on considering a Schur function as characteristic function of a contraction (see Section 1.2). This enables us outgoing from Schur parameters to construct a model of the corresponding contraction (see Section 2). In this model, the relative position of the largest shift and the largest coshift in a completely nonunitary contraction is described in Section 3 and then, based on this model, to find characteristics which are responsible for the pseudocontinuability of Schur functions (see Sections 4 and 5). The further parts of this paper (see Sections 6-8) admit applications of the above results to the study of properties of Schur functions and questions related with them.
Comment: arXiv admin note: text overlap with arXiv:1003.1670
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2312.17189
رقم الأكسشن: edsarx.2312.17189
قاعدة البيانات: arXiv