On some classes of unbounded operators
type: Item
instance of: scholarly article
title: On some classes of unbounded operators
zbMATH Open document ID: 0683.47031
DOI: 10.1007/BF01195114
author: Schôichi Ôta
author: Konrad Schmüdgen
published in: Integral Equations and Operator Theory
publication date: 1989-01-01T00:00:00Z
review text: The authors have investigated the notions of (formally) hyponormal and (formally) normal operators for unbounded operators and discussed the quasi-similarity of such operators. In particular, they have shown that quasi-similar unbounded normal operators are unitarily equivalent (which is an unbounded generalization of the Douglas theorem for the bounded normal operators) and a closed subnormal operator quasi-similar to a self-adjoint operator is self- adjoint.
Mathematics Subject Classification ID: 47L60
Mathematics Subject Classification ID: 47B20
zbMATH DE Number: 4119046
zbMATH Keywords: unbounded operators
zbMATH Keywords: quasi-similarity
zbMATH Keywords: quasi-similar unbounded normal operators
zbMATH Keywords: unbounded generalization of the Douglas theorem for the bounded normal operators
zbMATH Keywords: closed subnormal operator quasi-similar to a self-adjoint operator is self-adjoint
reviewed by: Ayumu Inoue
MaRDI profile type: Publication
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full work available at URL: https://doi.org/10.1007/bf01195114
OpenAlex ID: W2019398858
description: scientific article; zbMATH DE number 4119046