{"title":"$$\\lambda $$ -巴拿赫和双巴拿赫空间中的有限集","authors":"Aleena Philip, Manjul Gupta, Deepika Baweja","doi":"10.1007/s00574-024-00415-6","DOIUrl":null,"url":null,"abstract":"<p>In this paper, we introduce the notions of <span>\\(\\lambda \\)</span>-limited sets and <span>\\(\\lambda \\)</span>-<i>L</i>-sets in a Banach space <i>X</i> and its dual <span>\\(X^*\\)</span> respectively, using the vector valued sequence spaces <span>\\(\\lambda ^{w^*}(X^*)\\)</span> and <span>\\(\\lambda ^{w}(X)\\)</span>. We find characterizations for these sets in terms of absolutely <span>\\(\\lambda \\)</span>-summing operators and investigate the relationship between <span>\\(\\lambda \\)</span>-compact sets and <span>\\(\\lambda \\)</span>-limited sets, with a particular focus on the crucial role played by a norm iteration property. We also consider <span>\\(\\lambda \\)</span>-limited operators and show that this class is an operator ideal containing the ideal of <span>\\(\\lambda \\)</span>-compact operators for a suitably restricted <span>\\(\\lambda \\)</span>. Furthermore, we define a generalized Gelfand-Philips property for Banach spaces corresponding to an abstract sequence space.</p>","PeriodicalId":501417,"journal":{"name":"Bulletin of the Brazilian Mathematical Society, New Series","volume":"3 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"$$\\\\lambda $$ -Limited Sets in Banach and Dual Banach Spaces\",\"authors\":\"Aleena Philip, Manjul Gupta, Deepika Baweja\",\"doi\":\"10.1007/s00574-024-00415-6\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>In this paper, we introduce the notions of <span>\\\\(\\\\lambda \\\\)</span>-limited sets and <span>\\\\(\\\\lambda \\\\)</span>-<i>L</i>-sets in a Banach space <i>X</i> and its dual <span>\\\\(X^*\\\\)</span> respectively, using the vector valued sequence spaces <span>\\\\(\\\\lambda ^{w^*}(X^*)\\\\)</span> and <span>\\\\(\\\\lambda ^{w}(X)\\\\)</span>. We find characterizations for these sets in terms of absolutely <span>\\\\(\\\\lambda \\\\)</span>-summing operators and investigate the relationship between <span>\\\\(\\\\lambda \\\\)</span>-compact sets and <span>\\\\(\\\\lambda \\\\)</span>-limited sets, with a particular focus on the crucial role played by a norm iteration property. We also consider <span>\\\\(\\\\lambda \\\\)</span>-limited operators and show that this class is an operator ideal containing the ideal of <span>\\\\(\\\\lambda \\\\)</span>-compact operators for a suitably restricted <span>\\\\(\\\\lambda \\\\)</span>. Furthermore, we define a generalized Gelfand-Philips property for Banach spaces corresponding to an abstract sequence space.</p>\",\"PeriodicalId\":501417,\"journal\":{\"name\":\"Bulletin of the Brazilian Mathematical Society, New Series\",\"volume\":\"3 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-08-12\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Bulletin of the Brazilian Mathematical Society, New Series\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1007/s00574-024-00415-6\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of the Brazilian Mathematical Society, New Series","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1007/s00574-024-00415-6","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
$$\lambda $$ -Limited Sets in Banach and Dual Banach Spaces
In this paper, we introduce the notions of \(\lambda \)-limited sets and \(\lambda \)-L-sets in a Banach space X and its dual \(X^*\) respectively, using the vector valued sequence spaces \(\lambda ^{w^*}(X^*)\) and \(\lambda ^{w}(X)\). We find characterizations for these sets in terms of absolutely \(\lambda \)-summing operators and investigate the relationship between \(\lambda \)-compact sets and \(\lambda \)-limited sets, with a particular focus on the crucial role played by a norm iteration property. We also consider \(\lambda \)-limited operators and show that this class is an operator ideal containing the ideal of \(\lambda \)-compact operators for a suitably restricted \(\lambda \). Furthermore, we define a generalized Gelfand-Philips property for Banach spaces corresponding to an abstract sequence space.