{"title":"关于$C^b(K)的非等价范数$","authors":"A. Khoddami","doi":"10.22130/SCMA.2020.121559.748","DOIUrl":null,"url":null,"abstract":"Let $A$ be a non-zero normed vector space and let $K=overline{B_1^{(0)}}$ be the closed unit ball of $A$. Also, let $varphi$ be a non-zero element of $ A^*$ such that $Vert varphi Vertleq 1$. We first define a new norm $Vert cdot Vert_varphi$ on $C^b(K)$, that is a non-complete, non-algebraic norm and also non-equivalent to the norm $Vert cdot Vert_infty$. We next show that for $0neqpsiin A^*$ with $Vert psi Vertleq 1$, the two norms $Vert cdot Vert_varphi$ and $Vert cdot Vert_psi$ are equivalent if and only if $varphi$ and $psi$ are linearly dependent. Also by applying the norm $Vert cdot Vert_varphi $ and a new product `` $cdot$ '' on $C^b(K)$, we present the normed algebra $ left( C^{bvarphi}(K), Vert cdot Vert_varphi right)$. Finally we investigate some relations between strongly zero-product preserving maps on $C^b(K)$ and $C^{bvarphi}(K)$.","PeriodicalId":38924,"journal":{"name":"Communications in Mathematical Analysis","volume":"17 1","pages":"1-11"},"PeriodicalIF":0.0000,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Non-Equivalent Norms on $C^b(K)$\",\"authors\":\"A. Khoddami\",\"doi\":\"10.22130/SCMA.2020.121559.748\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Let $A$ be a non-zero normed vector space and let $K=overline{B_1^{(0)}}$ be the closed unit ball of $A$. Also, let $varphi$ be a non-zero element of $ A^*$ such that $Vert varphi Vertleq 1$. We first define a new norm $Vert cdot Vert_varphi$ on $C^b(K)$, that is a non-complete, non-algebraic norm and also non-equivalent to the norm $Vert cdot Vert_infty$. We next show that for $0neqpsiin A^*$ with $Vert psi Vertleq 1$, the two norms $Vert cdot Vert_varphi$ and $Vert cdot Vert_psi$ are equivalent if and only if $varphi$ and $psi$ are linearly dependent. Also by applying the norm $Vert cdot Vert_varphi $ and a new product `` $cdot$ '' on $C^b(K)$, we present the normed algebra $ left( C^{bvarphi}(K), Vert cdot Vert_varphi right)$. Finally we investigate some relations between strongly zero-product preserving maps on $C^b(K)$ and $C^{bvarphi}(K)$.\",\"PeriodicalId\":38924,\"journal\":{\"name\":\"Communications in Mathematical Analysis\",\"volume\":\"17 1\",\"pages\":\"1-11\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2020-11-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Communications in Mathematical Analysis\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.22130/SCMA.2020.121559.748\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"Mathematics\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Communications in Mathematical Analysis","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.22130/SCMA.2020.121559.748","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"Mathematics","Score":null,"Total":0}
Let $A$ be a non-zero normed vector space and let $K=overline{B_1^{(0)}}$ be the closed unit ball of $A$. Also, let $varphi$ be a non-zero element of $ A^*$ such that $Vert varphi Vertleq 1$. We first define a new norm $Vert cdot Vert_varphi$ on $C^b(K)$, that is a non-complete, non-algebraic norm and also non-equivalent to the norm $Vert cdot Vert_infty$. We next show that for $0neqpsiin A^*$ with $Vert psi Vertleq 1$, the two norms $Vert cdot Vert_varphi$ and $Vert cdot Vert_psi$ are equivalent if and only if $varphi$ and $psi$ are linearly dependent. Also by applying the norm $Vert cdot Vert_varphi $ and a new product `` $cdot$ '' on $C^b(K)$, we present the normed algebra $ left( C^{bvarphi}(K), Vert cdot Vert_varphi right)$. Finally we investigate some relations between strongly zero-product preserving maps on $C^b(K)$ and $C^{bvarphi}(K)$.