{"title":"A remark on the set of exactly approximable vectors in the simultaneous case","authors":"Reynold Fregoli","doi":"10.1090/proc/16790","DOIUrl":null,"url":null,"abstract":"<p>We compute the Hausdorff dimension of the set of <inline-formula content-type=\"math/mathml\">\n<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"psi\">\n <mml:semantics>\n <mml:mi>ψ</mml:mi>\n <mml:annotation encoding=\"application/x-tex\">\\psi</mml:annotation>\n </mml:semantics>\n</mml:math>\n</inline-formula>-exactly approximable vectors, in the simultaneous case, in dimension strictly larger than <inline-formula content-type=\"math/mathml\">\n<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"2\">\n <mml:semantics>\n <mml:mn>2</mml:mn>\n <mml:annotation encoding=\"application/x-tex\">2</mml:annotation>\n </mml:semantics>\n</mml:math>\n</inline-formula> and for approximating functions <inline-formula content-type=\"math/mathml\">\n<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"psi\">\n <mml:semantics>\n <mml:mi>ψ</mml:mi>\n <mml:annotation encoding=\"application/x-tex\">\\psi</mml:annotation>\n </mml:semantics>\n</mml:math>\n</inline-formula> with order at infinity less than or equal to <inline-formula content-type=\"math/mathml\">\n<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"negative 2\">\n <mml:semantics>\n <mml:mrow>\n <mml:mo>−</mml:mo>\n <mml:mn>2</mml:mn>\n </mml:mrow>\n <mml:annotation encoding=\"application/x-tex\">-2</mml:annotation>\n </mml:semantics>\n</mml:math>\n</inline-formula>. Our method relies on the analogous result in dimension <inline-formula content-type=\"math/mathml\">\n<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"1\">\n <mml:semantics>\n <mml:mn>1</mml:mn>\n <mml:annotation encoding=\"application/x-tex\">1</mml:annotation>\n </mml:semantics>\n</mml:math>\n</inline-formula>, proved by Yann Bugeaud and Carlos Moreira, and a version of Jarník’s theorem on fibres.</p>","PeriodicalId":0,"journal":{"name":"","volume":"49 46","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1090/proc/16790","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
We compute the Hausdorff dimension of the set of ψ\psi-exactly approximable vectors, in the simultaneous case, in dimension strictly larger than 22 and for approximating functions ψ\psi with order at infinity less than or equal to −2-2. Our method relies on the analogous result in dimension 11, proved by Yann Bugeaud and Carlos Moreira, and a version of Jarník’s theorem on fibres.