A criterion for uniqueness of a critical point in \(H_ 2\) rational approximation
type: Item
instance of: scholarly article
title: A criterion for uniqueness of a critical point in \(H_ 2\) rational approximation
zbMATH Open document ID: 0870.41013
DOI: 10.1007/BF02820445
published in: Journal d'Analyse Mathématique
publication date: 1997-09-02T00:00:00Z
review text: This paper presents a criterion for uniqueness of a critical point in \(H_{2, R}\) rational approximation of type \((m,n)\), with \(m\geq n-1\). This criterion is differential-topological in nature, and turns out to be connected with corona equations and classical interpolation theory. This paper also gives its use with three examples, namely best approximation of fixed type on small circles, a de Montessus de Ballore type theorem, and diagonal approximation to the exponential function of large degree.
Mathematics Subject Classification ID: 41A20
zbMATH DE Number: 1019379
zbMATH Keywords: uniqueness
zbMATH Keywords: critical point
zbMATH Keywords: rational approximation
author: L. Baratchart
author: E. B. Saff
author: F. Wielonsky
reviewed by: Yingguang Shi
MaRDI profile type: Publication
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full work available at URL: https://doi.org/10.1007/bf02820445
OpenAlex ID: W1973022041
description: scientific article; zbMATH DE number 1019379