Domingo García, Manuel Maestre, Miguel Martín, Óscar Roldán
{"title":"On Density and Bishop–Phelps–Bollobás-Type Properties for the Minimum Norm","authors":"Domingo García, Manuel Maestre, Miguel Martín, Óscar Roldán","doi":"10.1007/s00009-024-02705-1","DOIUrl":null,"url":null,"abstract":"<p>We study the set <span>\\({\\text {MA}}(X,Y)\\)</span> of operators between Banach spaces <i>X</i> and <i>Y</i> that attain their minimum norm, and the set <span>\\({\\text {QMA}}(X,Y)\\)</span> of operators that quasi attain their minimum norm. We characterize the Radon–Nikodym property in terms of operators that attain their minimum norm and obtain some related results about the density of the sets <span>\\({\\text {MA}}(X,Y)\\)</span> and <span>\\({\\text {QMA}}(X,Y)\\)</span>. We show that every infinite-dimensional Banach space <i>X</i> has an isomorphic space <i>Y</i>, such that not every operator from <i>X</i> to <i>Y</i> quasi attains its minimum norm. We introduce and study Bishop–Phelps–Bollobás type properties for the minimum norm, including the ones already considered in the literature, and we exhibit a wide variety of results and examples, as well as exploring the relations between them.</p>","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4000,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Accounts of Chemical Research","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1007/s00009-024-02705-1","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
We study the set \({\text {MA}}(X,Y)\) of operators between Banach spaces X and Y that attain their minimum norm, and the set \({\text {QMA}}(X,Y)\) of operators that quasi attain their minimum norm. We characterize the Radon–Nikodym property in terms of operators that attain their minimum norm and obtain some related results about the density of the sets \({\text {MA}}(X,Y)\) and \({\text {QMA}}(X,Y)\). We show that every infinite-dimensional Banach space X has an isomorphic space Y, such that not every operator from X to Y quasi attains its minimum norm. We introduce and study Bishop–Phelps–Bollobás type properties for the minimum norm, including the ones already considered in the literature, and we exhibit a wide variety of results and examples, as well as exploring the relations between them.
期刊介绍:
Accounts of Chemical Research presents short, concise and critical articles offering easy-to-read overviews of basic research and applications in all areas of chemistry and biochemistry. These short reviews focus on research from the author’s own laboratory and are designed to teach the reader about a research project. In addition, Accounts of Chemical Research publishes commentaries that give an informed opinion on a current research problem. Special Issues online are devoted to a single topic of unusual activity and significance.
Accounts of Chemical Research replaces the traditional article abstract with an article "Conspectus." These entries synopsize the research affording the reader a closer look at the content and significance of an article. Through this provision of a more detailed description of the article contents, the Conspectus enhances the article's discoverability by search engines and the exposure for the research.