{"title":"Quasi-isometric embeddings of \n \n \n \n C\n 0\n \n \n (\n K\n ,\n X\n )\n \n \n $C_{0}(K, X)$\n spaces which induce isometries whenever \n \n X\n $X$\n is a Hilbert space","authors":"Elói Medina Galego","doi":"10.1002/mana.12033","DOIUrl":null,"url":null,"abstract":"<p>Suppose that <span></span><math>\n <semantics>\n <mi>K</mi>\n <annotation>$K$</annotation>\n </semantics></math> and <span></span><math>\n <semantics>\n <mi>S</mi>\n <annotation>$S$</annotation>\n </semantics></math> are locally compact Hausdorff spaces and <span></span><math>\n <semantics>\n <mi>X</mi>\n <annotation>$X$</annotation>\n </semantics></math> is a Hilbert space. It is proven that if there exist real numbers <span></span><math>\n <semantics>\n <mrow>\n <mi>M</mi>\n <mo>≥</mo>\n <mn>1</mn>\n </mrow>\n <annotation>$M \\ge 1$</annotation>\n </semantics></math>, <span></span><math>\n <semantics>\n <mrow>\n <mi>L</mi>\n <mo>≥</mo>\n <mn>0</mn>\n </mrow>\n <annotation>$L \\ge 0$</annotation>\n </semantics></math> and a map <span></span><math>\n <semantics>\n <mi>T</mi>\n <annotation>$T$</annotation>\n </semantics></math> from <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>C</mi>\n <mn>0</mn>\n </msub>\n <mrow>\n <mo>(</mo>\n <mi>K</mi>\n <mo>,</mo>\n <mi>X</mi>\n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation>$C_{0}(K,X)$</annotation>\n </semantics></math> to <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>C</mi>\n <mn>0</mn>\n </msub>\n <mrow>\n <mo>(</mo>\n <mi>S</mi>\n <mo>,</mo>\n <mi>X</mi>\n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation>$C_{0}(S,X)$</annotation>\n </semantics></math> satisfying\n\n </p><p>In this case, as an immediate consequence, <span></span><math>\n <semantics>\n <mi>φ</mi>\n <annotation>$\\varphi$</annotation>\n </semantics></math> generates a linear isometry of <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>C</mi>\n <mn>0</mn>\n </msub>\n <mrow>\n <mo>(</mo>\n <mi>K</mi>\n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation>$C_{0}(K)$</annotation>\n </semantics></math> into <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>C</mi>\n <mn>0</mn>\n </msub>\n <mrow>\n <mo>(</mo>\n <msub>\n <mi>S</mi>\n <mn>0</mn>\n </msub>\n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation>$C_{0}(S_0)$</annotation>\n </semantics></math>. Even in the Lipschitz case (<span></span><math>\n <semantics>\n <mrow>\n <mi>L</mi>\n <mo>=</mo>\n <mn>0</mn>\n </mrow>\n <annotation>$L=0$</annotation>\n </semantics></math>), this result is the first nonlinear vector generalization of a classical Jarosz theorem (1984) concerning the into linear isomorphisms of spaces of continuous functions on locally compact Hausdorff spaces.</p>","PeriodicalId":49853,"journal":{"name":"Mathematische Nachrichten","volume":"298 9","pages":"2975-2985"},"PeriodicalIF":0.8000,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Mathematische Nachrichten","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/mana.12033","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
Suppose that and are locally compact Hausdorff spaces and is a Hilbert space. It is proven that if there exist real numbers , and a map from to satisfying
In this case, as an immediate consequence, generates a linear isometry of into . Even in the Lipschitz case (), this result is the first nonlinear vector generalization of a classical Jarosz theorem (1984) concerning the into linear isomorphisms of spaces of continuous functions on locally compact Hausdorff spaces.
期刊介绍:
Mathematische Nachrichten - Mathematical News publishes original papers on new results and methods that hold prospect for substantial progress in mathematics and its applications. All branches of analysis, algebra, number theory, geometry and topology, flow mechanics and theoretical aspects of stochastics are given special emphasis. Mathematische Nachrichten is indexed/abstracted in Current Contents/Physical, Chemical and Earth Sciences; Mathematical Review; Zentralblatt für Mathematik; Math Database on STN International, INSPEC; Science Citation Index