H∞ interpolation constrained by Beurling–Sobolev norms

We consider a Nevanlinna–Pick interpolation problem on finite sequences of the unit disc, constrained by Beurling–Sobolev norms. We find sharp asymptotics of the corresponding interpolation quantities, thereby improving the known estimates. On our way we obtain a S. M. Nikolskii type inequality for...

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Bibliographic Details
Main Authors: Baranov Anton, Zarouf Rachid
Format: Article
Language:English
Published: Sciendo 2023-05-01
Series:Moroccan Journal of Pure and Applied Analysis
Subjects:
Online Access:https://doi.org/10.2478/mjpaa-2023-0012
Description
Summary:We consider a Nevanlinna–Pick interpolation problem on finite sequences of the unit disc, constrained by Beurling–Sobolev norms. We find sharp asymptotics of the corresponding interpolation quantities, thereby improving the known estimates. On our way we obtain a S. M. Nikolskii type inequality for rational functions whose poles lie outside of the unit disc. It shows that the embedding of the Hardy space H2 into the Wiener algebra of absolutely convergent Fourier/Taylor series is invertible on the subset of rational functions of a given degree, whose poles remain at a given distance from the unit circle.
ISSN:2351-8227