English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In [19] there is an approach to the investigation of the pseudocontinuabilityof Schur functions in terms of Schur parameters. In particular, there wasobtained a criterion for the pseudocontinuability of Schur functions and theSchur parameters of rational Schur functions were described. This approach isbased on the description in terms of the Schur parameters of the relativeposition of the largest shift and the largest coshift in a completelynonunitary contraction. It should be mentioned that these results received afurther development in [8, 21-24].  This paper is aimed to give a survey about essential results on thisdirection. The main object in the approach is based on considering a Schurfunction as characteristic function of a contraction (see Section 1.2). Thisenables us outgoing from Schur parameters to construct a model of thecorresponding contraction (see Section 2). In this model, the relative positionof the largest shift and the largest coshift in a completely nonunitarycontraction is described in Section 3 and then, based on this model, to findcharacteristics which are responsible for the pseudocontinuability of Schurfunctions (see Sections 4 and 5). The further parts of this paper (see Sections6-8) admit applications of the above results to the study of properties ofSchur functions and questions related with them.

Characteristic Function, Schur Parameters and Pseudocontinuation of Schur functions