Josef Greilhuber, Carl Schildkraut, Jonathan Tidor
{"title":"任意范数中更多的单位距离","authors":"Josef Greilhuber, Carl Schildkraut, Jonathan Tidor","doi":"10.1112/blms.70133","DOIUrl":null,"url":null,"abstract":"<p>For <span></span><math>\n <semantics>\n <mrow>\n <mi>d</mi>\n <mo>⩾</mo>\n <mn>2</mn>\n </mrow>\n <annotation>$d\\geqslant 2$</annotation>\n </semantics></math> and any norm on <span></span><math>\n <semantics>\n <msup>\n <mi>R</mi>\n <mi>d</mi>\n </msup>\n <annotation>$\\mathbb {R}^d$</annotation>\n </semantics></math>, we prove that there exists a set of <span></span><math>\n <semantics>\n <mi>n</mi>\n <annotation>$n$</annotation>\n </semantics></math> points that spans at least <span></span><math>\n <semantics>\n <mrow>\n <mrow>\n <mo>(</mo>\n <mstyle>\n <mfrac>\n <mi>d</mi>\n <mn>2</mn>\n </mfrac>\n </mstyle>\n <mo>−</mo>\n <mi>o</mi>\n <mrow>\n <mo>(</mo>\n <mn>1</mn>\n <mo>)</mo>\n </mrow>\n <mo>)</mo>\n </mrow>\n <mi>n</mi>\n <msub>\n <mi>log</mi>\n <mn>2</mn>\n </msub>\n <mi>n</mi>\n </mrow>\n <annotation>$(\\tfrac{d}{2}-o(1))n\\log _2n$</annotation>\n </semantics></math> unit distances under this norm for every <span></span><math>\n <semantics>\n <mi>n</mi>\n <annotation>$n$</annotation>\n </semantics></math>. This matches the upper bound recently proved by Alon, Bucić, and Sauermann for typical norms (i.e., norms lying in a comeagre set). We also show that for <span></span><math>\n <semantics>\n <mrow>\n <mi>d</mi>\n <mo>⩾</mo>\n <mn>3</mn>\n </mrow>\n <annotation>$d\\geqslant 3$</annotation>\n </semantics></math> and a typical norm on <span></span><math>\n <semantics>\n <msup>\n <mi>R</mi>\n <mi>d</mi>\n </msup>\n <annotation>$\\mathbb {R}^d$</annotation>\n </semantics></math>, the unit distance graph of this norm contains a copy of <span></span><math>\n <semantics>\n <msub>\n <mi>K</mi>\n <mrow>\n <mi>d</mi>\n <mo>,</mo>\n <mi>m</mi>\n </mrow>\n </msub>\n <annotation>$K_{d,m}$</annotation>\n </semantics></math> for all <span></span><math>\n <semantics>\n <mi>m</mi>\n <annotation>$m$</annotation>\n </semantics></math>.</p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 9","pages":"2885-2901"},"PeriodicalIF":0.9000,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"More unit distances in arbitrary norms\",\"authors\":\"Josef Greilhuber, Carl Schildkraut, Jonathan Tidor\",\"doi\":\"10.1112/blms.70133\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>For <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>d</mi>\\n <mo>⩾</mo>\\n <mn>2</mn>\\n </mrow>\\n <annotation>$d\\\\geqslant 2$</annotation>\\n </semantics></math> and any norm on <span></span><math>\\n <semantics>\\n <msup>\\n <mi>R</mi>\\n <mi>d</mi>\\n </msup>\\n <annotation>$\\\\mathbb {R}^d$</annotation>\\n </semantics></math>, we prove that there exists a set of <span></span><math>\\n <semantics>\\n <mi>n</mi>\\n <annotation>$n$</annotation>\\n </semantics></math> points that spans at least <span></span><math>\\n <semantics>\\n <mrow>\\n <mrow>\\n <mo>(</mo>\\n <mstyle>\\n <mfrac>\\n <mi>d</mi>\\n <mn>2</mn>\\n </mfrac>\\n </mstyle>\\n <mo>−</mo>\\n <mi>o</mi>\\n <mrow>\\n <mo>(</mo>\\n <mn>1</mn>\\n <mo>)</mo>\\n </mrow>\\n <mo>)</mo>\\n </mrow>\\n <mi>n</mi>\\n <msub>\\n <mi>log</mi>\\n <mn>2</mn>\\n </msub>\\n <mi>n</mi>\\n </mrow>\\n <annotation>$(\\\\tfrac{d}{2}-o(1))n\\\\log _2n$</annotation>\\n </semantics></math> unit distances under this norm for every <span></span><math>\\n <semantics>\\n <mi>n</mi>\\n <annotation>$n$</annotation>\\n </semantics></math>. This matches the upper bound recently proved by Alon, Bucić, and Sauermann for typical norms (i.e., norms lying in a comeagre set). We also show that for <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>d</mi>\\n <mo>⩾</mo>\\n <mn>3</mn>\\n </mrow>\\n <annotation>$d\\\\geqslant 3$</annotation>\\n </semantics></math> and a typical norm on <span></span><math>\\n <semantics>\\n <msup>\\n <mi>R</mi>\\n <mi>d</mi>\\n </msup>\\n <annotation>$\\\\mathbb {R}^d$</annotation>\\n </semantics></math>, the unit distance graph of this norm contains a copy of <span></span><math>\\n <semantics>\\n <msub>\\n <mi>K</mi>\\n <mrow>\\n <mi>d</mi>\\n <mo>,</mo>\\n <mi>m</mi>\\n </mrow>\\n </msub>\\n <annotation>$K_{d,m}$</annotation>\\n </semantics></math> for all <span></span><math>\\n <semantics>\\n <mi>m</mi>\\n <annotation>$m$</annotation>\\n </semantics></math>.</p>\",\"PeriodicalId\":55298,\"journal\":{\"name\":\"Bulletin of the London Mathematical Society\",\"volume\":\"57 9\",\"pages\":\"2885-2901\"},\"PeriodicalIF\":0.9000,\"publicationDate\":\"2025-07-29\",\"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://londmathsoc.onlinelibrary.wiley.com/doi/10.1112/blms.70133\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of the London Mathematical Society","FirstCategoryId":"100","ListUrlMain":"https://londmathsoc.onlinelibrary.wiley.com/doi/10.1112/blms.70133","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
摘要
对于d小于2 $d\geqslant 2$和R d $\mathbb {R}^d$上的任何规范,我们证明了存在一个n个$n$点的集合,它张成至少(d 2−o (1))) n log 2 n $(\tfrac{d}{2}-o(1))n\log _2n$在这个范数下的单位距离对于每一个n $n$。这与最近由Alon, buciki和Sauermann证明的典型范数(即,位于一个趋同集中的范数)的上界相匹配。我们还显示,对于d小于3 $d\geqslant 3$和R d $\mathbb {R}^d$上的典型范数,该范数的单位距离图包含K d的副本,M $K_{d,m}$代表所有M $m$。
For and any norm on , we prove that there exists a set of points that spans at least unit distances under this norm for every . This matches the upper bound recently proved by Alon, Bucić, and Sauermann for typical norms (i.e., norms lying in a comeagre set). We also show that for and a typical norm on , the unit distance graph of this norm contains a copy of for all .