{"title":"Norm attaining bilinear forms of ${\\mathcal L}(^2 d_{*}(1, w)^2)$ at given vectors","authors":"S.G. Kim","doi":"10.15421/242313","DOIUrl":null,"url":null,"abstract":"For given unit vectors $x_1, \\cdots, x_n$ of a real Banach space $E,$ we define $$NA({\\mathcal L}(^nE))(x_1, \\cdots, x_n)=\\{T\\in {\\mathcal L}(^nE): |T(x_1, \\cdots, x_n)|=\\|T\\|=1\\},$$ where ${\\mathcal L}(^nE)$ denotes the Banach space of all continuous $n$-linear forms on $E$ endowed with the norm $\\|T\\|=\\sup_{\\|x_k\\|=1, 1\\leq k\\leq n}{|T(x_1, \\ldots, x_n)|}$.In this paper, we classify $NA({\\mathcal L}(^2 d_{*}(1, w)^2))(Z_1, Z_2)$ for unit vectors $Z_1, Z_2\\in d_{*}(1, w)^2,$ where $d_{*}(1, w)^2=\\mathbb{R}^2$ with the norm of weight $0<w<1$ endowed with $\\|(x, y)\\|_{d_*(1, w)}=\\max\\Big\\{|x|, |y|, \\frac{|x|+|y|}{1+w}\\Big\\}$.","PeriodicalId":52827,"journal":{"name":"Researches in Mathematics","volume":"8 4","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Researches in Mathematics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.15421/242313","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"Mathematics","Score":null,"Total":0}
引用次数: 0
Abstract
For given unit vectors $x_1, \cdots, x_n$ of a real Banach space $E,$ we define $$NA({\mathcal L}(^nE))(x_1, \cdots, x_n)=\{T\in {\mathcal L}(^nE): |T(x_1, \cdots, x_n)|=\|T\|=1\},$$ where ${\mathcal L}(^nE)$ denotes the Banach space of all continuous $n$-linear forms on $E$ endowed with the norm $\|T\|=\sup_{\|x_k\|=1, 1\leq k\leq n}{|T(x_1, \ldots, x_n)|}$.In this paper, we classify $NA({\mathcal L}(^2 d_{*}(1, w)^2))(Z_1, Z_2)$ for unit vectors $Z_1, Z_2\in d_{*}(1, w)^2,$ where $d_{*}(1, w)^2=\mathbb{R}^2$ with the norm of weight $0