{"title":"On the Pólya conjecture for the Neumann problem in planar convex domains","authors":"N. Filonov","doi":"10.1002/cpa.22231","DOIUrl":null,"url":null,"abstract":"<p>Denote by <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>N</mi>\n <mi>N</mi>\n </msub>\n <mrow>\n <mo>(</mo>\n <mi>Ω</mi>\n <mo>,</mo>\n <mi>λ</mi>\n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation>$N_{\\cal N} (\\Omega,\\lambda)$</annotation>\n </semantics></math> the counting function of the spectrum of the Neumann problem in the domain <span></span><math>\n <semantics>\n <mi>Ω</mi>\n <annotation>$\\Omega$</annotation>\n </semantics></math> on the plane. G. Pólya conjectured that <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>N</mi>\n <mi>N</mi>\n </msub>\n <mrow>\n <mo>(</mo>\n <mi>Ω</mi>\n <mo>,</mo>\n <mi>λ</mi>\n <mo>)</mo>\n </mrow>\n <mo>⩾</mo>\n <msup>\n <mrow>\n <mo>(</mo>\n <mn>4</mn>\n <mi>π</mi>\n <mo>)</mo>\n </mrow>\n <mrow>\n <mo>−</mo>\n <mn>1</mn>\n </mrow>\n </msup>\n <mrow>\n <mo>|</mo>\n <mi>Ω</mi>\n <mo>|</mo>\n </mrow>\n <mi>λ</mi>\n </mrow>\n <annotation>$N_{\\cal N} (\\Omega,\\lambda) \\geqslant (4\\pi)^{-1} |\\Omega | \\lambda$</annotation>\n </semantics></math>. We prove that for convex domains <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>N</mi>\n <mi>N</mi>\n </msub>\n <mrow>\n <mo>(</mo>\n <mi>Ω</mi>\n <mo>,</mo>\n <mi>λ</mi>\n <mo>)</mo>\n </mrow>\n <mo>⩾</mo>\n <msup>\n <mrow>\n <mo>(</mo>\n <mn>2</mn>\n <msqrt>\n <mn>3</mn>\n </msqrt>\n <mspace></mspace>\n <msubsup>\n <mi>j</mi>\n <mn>0</mn>\n <mn>2</mn>\n </msubsup>\n <mo>)</mo>\n </mrow>\n <mrow>\n <mo>−</mo>\n <mn>1</mn>\n </mrow>\n </msup>\n <mrow>\n <mo>|</mo>\n <mi>Ω</mi>\n <mo>|</mo>\n </mrow>\n <mi>λ</mi>\n </mrow>\n <annotation>$N_{\\cal N} (\\Omega,\\lambda) \\geqslant (2 \\sqrt 3 \\,j_0^2)^{-1} |\\Omega | \\lambda$</annotation>\n </semantics></math>. Here <span></span><math>\n <semantics>\n <msub>\n <mi>j</mi>\n <mn>0</mn>\n </msub>\n <annotation>$j_0$</annotation>\n </semantics></math> is the first zero of the Bessel function <span></span><math>\n <semantics>\n <msub>\n <mi>J</mi>\n <mn>0</mn>\n </msub>\n <annotation>$J_0$</annotation>\n </semantics></math>.</p>","PeriodicalId":10601,"journal":{"name":"Communications on Pure and Applied Mathematics","volume":"78 3","pages":"537-544"},"PeriodicalIF":3.1000,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Communications on Pure and Applied Mathematics","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/cpa.22231","RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Denote by the counting function of the spectrum of the Neumann problem in the domain on the plane. G. Pólya conjectured that . We prove that for convex domains . Here is the first zero of the Bessel function .