{"title":"Characterizations of generalized pencils of pairs of projections","authors":"Tao Chen, Weining Lai, Chunyuan Deng","doi":"10.1007/s43037-023-00322-w","DOIUrl":null,"url":null,"abstract":"<p>Let <i>T</i> be a bounded linear operator on a complex Hilbert space <span>\\(\\mathcal {H}\\)</span>. We present some necessary and sufficient conditions for <i>T</i> to be the generalized pencil <span>\\(P + \\alpha Q +\\beta PQ\\)</span> of a pair (<i>P</i>, <i>Q</i>) of projections at some point <span>\\((\\alpha , \\beta )\\in \\mathbb {C}^2\\)</span>. The range and kernel relations of the generalized pencil <i>T</i> are studied and comments on the additional properties of some special generalized pencil are given.</p>","PeriodicalId":55400,"journal":{"name":"Banach Journal of Mathematical Analysis","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Banach Journal of Mathematical Analysis","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1007/s43037-023-00322-w","RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Let T be a bounded linear operator on a complex Hilbert space \(\mathcal {H}\). We present some necessary and sufficient conditions for T to be the generalized pencil \(P + \alpha Q +\beta PQ\) of a pair (P, Q) of projections at some point \((\alpha , \beta )\in \mathbb {C}^2\). The range and kernel relations of the generalized pencil T are studied and comments on the additional properties of some special generalized pencil are given.
期刊介绍:
The Banach Journal of Mathematical Analysis (Banach J. Math. Anal.) is published by Birkhäuser on behalf of the Tusi Mathematical Research Group.
Banach J. Math. Anal. is a peer-reviewed electronic journal publishing papers of high standards with deep results, new ideas, profound impact, and significant implications in all areas of functional analysis and operator theory and all modern related topics. Banach J. Math. Anal. normally publishes survey articles and original research papers numbering 15 pages or more in the journal’s style. Shorter papers may be submitted to the Annals of Functional Analysis or Advances in Operator Theory.