{"title":"最小范数和克劳福德数获得算子的本地化Bishop-Phelps-Bollobás类型属性","authors":"Uday Shankar Chakraborty","doi":"10.1007/s43036-024-00415-9","DOIUrl":null,"url":null,"abstract":"<div><p>In this paper, we study the approximate minimizing property (AMp) for operators, a localized Bishop-Phelps-Bollobás type property with respect to the minimum norm. Given Banach spaces <i>X</i> and <i>Y</i> we define a new class <span>\\(\\mathcal{A}\\mathcal{M}(X,Y)\\)</span> of bounded linear operators from <i>X</i> to <i>Y</i> for which the pair (<i>X</i>, <i>Y</i>) satisfies the AMp. We provide a necessary and sufficient condition for non-injective operators from <i>X</i> to <i>Y</i> to be in the class <span>\\(\\mathcal{A}\\mathcal{M}(X,Y)\\)</span>. We also prove that <i>X</i> is finite dimensional if and only if for every Banach space <i>Y</i>, (<i>X</i>, <i>Y</i>) has the AMp for all minimum norm attaining operators from <i>X</i> to <i>Y</i> if and only if for every Banach space <i>Y</i>, (<i>Y</i>, <i>X</i>) has the AMp for all minimum norm attaining operators from <i>Y</i> to <i>X</i>. We also study the AMp with respect to Crawford number called AMp-<i>c</i> for operators.</p></div>","PeriodicalId":44371,"journal":{"name":"Advances in Operator Theory","volume":"10 1","pages":""},"PeriodicalIF":0.8000,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Localized Bishop-Phelps-Bollobás type properties for minimum norm and Crawford number attaining operators\",\"authors\":\"Uday Shankar Chakraborty\",\"doi\":\"10.1007/s43036-024-00415-9\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>In this paper, we study the approximate minimizing property (AMp) for operators, a localized Bishop-Phelps-Bollobás type property with respect to the minimum norm. Given Banach spaces <i>X</i> and <i>Y</i> we define a new class <span>\\\\(\\\\mathcal{A}\\\\mathcal{M}(X,Y)\\\\)</span> of bounded linear operators from <i>X</i> to <i>Y</i> for which the pair (<i>X</i>, <i>Y</i>) satisfies the AMp. We provide a necessary and sufficient condition for non-injective operators from <i>X</i> to <i>Y</i> to be in the class <span>\\\\(\\\\mathcal{A}\\\\mathcal{M}(X,Y)\\\\)</span>. We also prove that <i>X</i> is finite dimensional if and only if for every Banach space <i>Y</i>, (<i>X</i>, <i>Y</i>) has the AMp for all minimum norm attaining operators from <i>X</i> to <i>Y</i> if and only if for every Banach space <i>Y</i>, (<i>Y</i>, <i>X</i>) has the AMp for all minimum norm attaining operators from <i>Y</i> to <i>X</i>. We also study the AMp with respect to Crawford number called AMp-<i>c</i> for operators.</p></div>\",\"PeriodicalId\":44371,\"journal\":{\"name\":\"Advances in Operator Theory\",\"volume\":\"10 1\",\"pages\":\"\"},\"PeriodicalIF\":0.8000,\"publicationDate\":\"2025-01-13\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Advances in Operator Theory\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s43036-024-00415-9\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advances in Operator Theory","FirstCategoryId":"1085","ListUrlMain":"https://link.springer.com/article/10.1007/s43036-024-00415-9","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
Localized Bishop-Phelps-Bollobás type properties for minimum norm and Crawford number attaining operators
In this paper, we study the approximate minimizing property (AMp) for operators, a localized Bishop-Phelps-Bollobás type property with respect to the minimum norm. Given Banach spaces X and Y we define a new class \(\mathcal{A}\mathcal{M}(X,Y)\) of bounded linear operators from X to Y for which the pair (X, Y) satisfies the AMp. We provide a necessary and sufficient condition for non-injective operators from X to Y to be in the class \(\mathcal{A}\mathcal{M}(X,Y)\). We also prove that X is finite dimensional if and only if for every Banach space Y, (X, Y) has the AMp for all minimum norm attaining operators from X to Y if and only if for every Banach space Y, (Y, X) has the AMp for all minimum norm attaining operators from Y to X. We also study the AMp with respect to Crawford number called AMp-c for operators.