{"title":"Delta-points in Banach spaces generated by adequate families","authors":"T. Abrahamsen, Vegard Lima, Andr'e Martiny","doi":"10.1215/00192082-10123638","DOIUrl":null,"url":null,"abstract":"We study delta-points in Banach spaces $h_{\\mathcal{A},p}$ generated by adequate families $\\mathcal A$ where $1 \\le p 1$ we prove that neither $h_{\\mathcal{A},p}$ nor its dual contain delta-points. Under the extra assumption that $\\mathcal A$ is regular, we prove that the same is true when $p=1.$ In particular the Schreier spaces and their duals fail to have delta-points. If $\\mathcal A$ consists of finite sets only we are able to rule out the existence of delta-points in $h_{\\mathcal{A},1}$ and Daugavet-points in its dual. We also show that if $h_{\\mathcal{A},1}$ is polyhedral, then it is either (I)-polyhedral or (V)-polyhedral (in the sense of Fonf and Vesel\\'y).","PeriodicalId":56298,"journal":{"name":"Illinois Journal of Mathematics","volume":" ","pages":""},"PeriodicalIF":0.6000,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"4","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Illinois Journal of Mathematics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1215/00192082-10123638","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 4
Abstract
We study delta-points in Banach spaces $h_{\mathcal{A},p}$ generated by adequate families $\mathcal A$ where $1 \le p 1$ we prove that neither $h_{\mathcal{A},p}$ nor its dual contain delta-points. Under the extra assumption that $\mathcal A$ is regular, we prove that the same is true when $p=1.$ In particular the Schreier spaces and their duals fail to have delta-points. If $\mathcal A$ consists of finite sets only we are able to rule out the existence of delta-points in $h_{\mathcal{A},1}$ and Daugavet-points in its dual. We also show that if $h_{\mathcal{A},1}$ is polyhedral, then it is either (I)-polyhedral or (V)-polyhedral (in the sense of Fonf and Vesel\'y).
期刊介绍:
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