{"title":"A Banach space theoretical characterization of abelian 𝐶*-algebras","authors":"Ryotaro Tanaka","doi":"10.1090/bproc/175","DOIUrl":null,"url":null,"abstract":"<p>A Banach space theoretical characterization of abelian <inline-formula content-type=\"math/mathml\">\n<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper C Superscript asterisk\">\n <mml:semantics>\n <mml:msup>\n <mml:mi>C</mml:mi>\n <mml:mo>∗<!-- ∗ --></mml:mo>\n </mml:msup>\n <mml:annotation encoding=\"application/x-tex\">C^*</mml:annotation>\n </mml:semantics>\n</mml:math>\n</inline-formula>- algebras among all <inline-formula content-type=\"math/mathml\">\n<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper C Superscript asterisk\">\n <mml:semantics>\n <mml:msup>\n <mml:mi>C</mml:mi>\n <mml:mo>∗<!-- ∗ --></mml:mo>\n </mml:msup>\n <mml:annotation encoding=\"application/x-tex\">C^*</mml:annotation>\n </mml:semantics>\n</mml:math>\n</inline-formula>-algebras is given. As an application, it is shown that if <inline-formula content-type=\"math/mathml\">\n<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper A\">\n <mml:semantics>\n <mml:mi>A</mml:mi>\n <mml:annotation encoding=\"application/x-tex\">A</mml:annotation>\n </mml:semantics>\n</mml:math>\n</inline-formula> and <inline-formula content-type=\"math/mathml\">\n<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper B\">\n <mml:semantics>\n <mml:mi>B</mml:mi>\n <mml:annotation encoding=\"application/x-tex\">B</mml:annotation>\n </mml:semantics>\n</mml:math>\n</inline-formula> are <inline-formula content-type=\"math/mathml\">\n<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper C Superscript asterisk\">\n <mml:semantics>\n <mml:msup>\n <mml:mi>C</mml:mi>\n <mml:mo>∗<!-- ∗ --></mml:mo>\n </mml:msup>\n <mml:annotation encoding=\"application/x-tex\">C^*</mml:annotation>\n </mml:semantics>\n</mml:math>\n</inline-formula>-algebras (nonlinearly) isomorphic to each other with respect to the structure of Birkhoff-James orthogonality, and if either <inline-formula content-type=\"math/mathml\">\n<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper A\">\n <mml:semantics>\n <mml:mi>A</mml:mi>\n <mml:annotation encoding=\"application/x-tex\">A</mml:annotation>\n </mml:semantics>\n</mml:math>\n</inline-formula> or <inline-formula content-type=\"math/mathml\">\n<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper B\">\n <mml:semantics>\n <mml:mi>B</mml:mi>\n <mml:annotation encoding=\"application/x-tex\">B</mml:annotation>\n </mml:semantics>\n</mml:math>\n</inline-formula> is abelian, then they are <inline-formula content-type=\"math/mathml\">\n<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"asterisk\">\n <mml:semantics>\n <mml:mo>∗<!-- ∗ --></mml:mo>\n <mml:annotation encoding=\"application/x-tex\">*</mml:annotation>\n </mml:semantics>\n</mml:math>\n</inline-formula>-isomorphic. Moreover, it is pointed out that the same kind of characterization is not valid for preduals of abelian von Neumann algebras.</p>","PeriodicalId":106316,"journal":{"name":"Proceedings of the American Mathematical Society, Series B","volume":"1 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Proceedings of the American Mathematical Society, Series B","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1090/bproc/175","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 1
Abstract
A Banach space theoretical characterization of abelian C∗C^*- algebras among all C∗C^*-algebras is given. As an application, it is shown that if AA and BB are C∗C^*-algebras (nonlinearly) isomorphic to each other with respect to the structure of Birkhoff-James orthogonality, and if either AA or BB is abelian, then they are ∗*-isomorphic. Moreover, it is pointed out that the same kind of characterization is not valid for preduals of abelian von Neumann algebras.