{"title":"Continuous actions on primitive ideal spaces lift to \n \n \n C\n *\n \n $\\mathrm{C}^\\ast$\n -actions","authors":"Matteo Pagliero","doi":"10.1112/blms.13203","DOIUrl":null,"url":null,"abstract":"<p>We prove that for any second-countable, locally compact group <span></span><math>\n <semantics>\n <mi>G</mi>\n <annotation>$G$</annotation>\n </semantics></math>, any continuous <span></span><math>\n <semantics>\n <mi>G</mi>\n <annotation>$G$</annotation>\n </semantics></math>-action on the primitive ideal space of a separable, nuclear <span></span><math>\n <semantics>\n <msup>\n <mi>C</mi>\n <mo>*</mo>\n </msup>\n <annotation>$\\mathrm{C}^\\ast$</annotation>\n </semantics></math>-algebra <span></span><math>\n <semantics>\n <mi>B</mi>\n <annotation>$B$</annotation>\n </semantics></math> such that <span></span><math>\n <semantics>\n <mrow>\n <mi>B</mi>\n <mo>≅</mo>\n <mi>B</mi>\n <mo>⊗</mo>\n <msub>\n <mi>O</mi>\n <mn>2</mn>\n </msub>\n <mo>⊗</mo>\n <mi>K</mi>\n </mrow>\n <annotation>$B \\cong B\\otimes \\mathcal {O}_2\\otimes \\mathcal {K}$</annotation>\n </semantics></math> is induced by an action on <span></span><math>\n <semantics>\n <mi>B</mi>\n <annotation>$B$</annotation>\n </semantics></math>. As a direct consequence, we establish that every continuous action on the primitive ideal space of a separable, nuclear <span></span><math>\n <semantics>\n <msup>\n <mi>C</mi>\n <mo>*</mo>\n </msup>\n <annotation>$\\mathrm{C}^\\ast$</annotation>\n </semantics></math>-algebra is induced by an action on a <span></span><math>\n <semantics>\n <msup>\n <mi>C</mi>\n <mo>*</mo>\n </msup>\n <annotation>$\\mathrm{C}^\\ast$</annotation>\n </semantics></math>-algebra with the same primitive ideal space. Moreover, we discuss an application to the classification of equivariantly <span></span><math>\n <semantics>\n <msub>\n <mi>O</mi>\n <mn>2</mn>\n </msub>\n <annotation>$\\mathcal {O}_2$</annotation>\n </semantics></math>-stable actions.</p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 2","pages":"404-425"},"PeriodicalIF":0.8000,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of the London Mathematical Society","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1112/blms.13203","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
We prove that for any second-countable, locally compact group , any continuous -action on the primitive ideal space of a separable, nuclear -algebra such that is induced by an action on . As a direct consequence, we establish that every continuous action on the primitive ideal space of a separable, nuclear -algebra is induced by an action on a -algebra with the same primitive ideal space. Moreover, we discuss an application to the classification of equivariantly -stable actions.