Quadratically hyponormal weighted shifts with two equal weights
type: Item
instance of: scholarly article
title: Quadratically hyponormal weighted shifts with two equal weights
zbMATH Open document ID: 0961.47017
DOI: 10.1007/BF01192423
author: Raúl E. Curto
author: Il Bong Jung
published in: Integral Equations and Operator Theory
publication date: 2001-05-21T00:00:00Z
review text: The planar set \({\mathcal R}\) of all pairs \((x,y)\) with the property that the weighted shift \(W_{1,(1,\sqrt x,\sqrt y)^{\wedge}}\) is positively quadratically hyponormal is shown to be closed convex with nonempty interior. The boundary of \({\mathcal R}\) is also described in terms of these data.
Mathematics Subject Classification ID: 47B37
Mathematics Subject Classification ID: 47B20
Mathematics Subject Classification ID: 47A57
Mathematics Subject Classification ID: 47-04
zbMATH DE Number: 1507907
zbMATH Keywords: hyponormal operator
zbMATH Keywords: weighted shift
zbMATH Keywords: planar closed convex set
zbMATH Keywords: boundary
zbMATH Keywords: positively quadratically hyponormal
reviewed by: Mihai Turinici
describes a project that uses: Mathematica
MaRDI profile type: Publication
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full work available at URL: https://doi.org/10.1007/bf01192423
OpenAlex ID: W2007321714
description: scientific article; zbMATH DE number 1507907