{"title":"局部波尔洛巴斯类型属性的弱化与巴拿赫空间的几何学","authors":"Uday Shankar Chakraborty","doi":"10.1007/s44146-023-00095-6","DOIUrl":null,"url":null,"abstract":"<div><p>This paper deals with a weaker form of the property so called <span>\\({\\textbf {L}}_{o,o}\\)</span> for operators, which we call the property weak <span>\\({\\textbf {L}}_{o,o}\\)</span> for operators. We characterize this property in terms of convergence of approximate norm attainment sets and prove that a pair of Banach spaces (<i>X</i>, <i>Y</i>) satisfies the property weak <span>\\({\\textbf {L}}_{o,o}\\)</span> for compact operators if and only if <i>X</i> is reflexive. We further investigate the property weak <span>\\({\\textbf {L}}_{o,o}\\)</span> for bilinear maps and obtain a connection of it with the property weak <span>\\({\\textbf {L}}_{o,o}\\)</span> for operators. Importantly, we also characterize some geometric properties of Banach spaces with the help of convergence of approximate norm attainment sets.</p></div>","PeriodicalId":46939,"journal":{"name":"ACTA SCIENTIARUM MATHEMATICARUM","volume":"90 1-2","pages":"91 - 108"},"PeriodicalIF":0.5000,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Weakening of a local Bollobás type property and geometry of Banach spaces\",\"authors\":\"Uday Shankar Chakraborty\",\"doi\":\"10.1007/s44146-023-00095-6\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>This paper deals with a weaker form of the property so called <span>\\\\({\\\\textbf {L}}_{o,o}\\\\)</span> for operators, which we call the property weak <span>\\\\({\\\\textbf {L}}_{o,o}\\\\)</span> for operators. We characterize this property in terms of convergence of approximate norm attainment sets and prove that a pair of Banach spaces (<i>X</i>, <i>Y</i>) satisfies the property weak <span>\\\\({\\\\textbf {L}}_{o,o}\\\\)</span> for compact operators if and only if <i>X</i> is reflexive. We further investigate the property weak <span>\\\\({\\\\textbf {L}}_{o,o}\\\\)</span> for bilinear maps and obtain a connection of it with the property weak <span>\\\\({\\\\textbf {L}}_{o,o}\\\\)</span> for operators. Importantly, we also characterize some geometric properties of Banach spaces with the help of convergence of approximate norm attainment sets.</p></div>\",\"PeriodicalId\":46939,\"journal\":{\"name\":\"ACTA SCIENTIARUM MATHEMATICARUM\",\"volume\":\"90 1-2\",\"pages\":\"91 - 108\"},\"PeriodicalIF\":0.5000,\"publicationDate\":\"2023-09-18\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"ACTA SCIENTIARUM MATHEMATICARUM\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s44146-023-00095-6\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACTA SCIENTIARUM MATHEMATICARUM","FirstCategoryId":"1085","ListUrlMain":"https://link.springer.com/article/10.1007/s44146-023-00095-6","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
Weakening of a local Bollobás type property and geometry of Banach spaces
This paper deals with a weaker form of the property so called \({\textbf {L}}_{o,o}\) for operators, which we call the property weak \({\textbf {L}}_{o,o}\) for operators. We characterize this property in terms of convergence of approximate norm attainment sets and prove that a pair of Banach spaces (X, Y) satisfies the property weak \({\textbf {L}}_{o,o}\) for compact operators if and only if X is reflexive. We further investigate the property weak \({\textbf {L}}_{o,o}\) for bilinear maps and obtain a connection of it with the property weak \({\textbf {L}}_{o,o}\) for operators. Importantly, we also characterize some geometric properties of Banach spaces with the help of convergence of approximate norm attainment sets.