{"title":"范德华登数的新下界","authors":"B. Green","doi":"10.1017/fmp.2022.12","DOIUrl":null,"url":null,"abstract":"Abstract We show that there is a red-blue colouring of $[N]$ with no blue 3-term arithmetic progression and no red arithmetic progression of length $e^{C(\\log N)^{3/4}(\\log \\log N)^{1/4}}$. Consequently, the two-colour van der Waerden number $w(3,k)$ is bounded below by $k^{b(k)}$, where $b(k) = c \\big ( \\frac {\\log k}{\\log \\log k} \\big )^{1/3}$. Previously it had been speculated, supported by data, that $w(3,k) = O(k^2)$.","PeriodicalId":56024,"journal":{"name":"Forum of Mathematics Pi","volume":" ","pages":""},"PeriodicalIF":2.8000,"publicationDate":"2021-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"New lower bounds for van der Waerden numbers\",\"authors\":\"B. Green\",\"doi\":\"10.1017/fmp.2022.12\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract We show that there is a red-blue colouring of $[N]$ with no blue 3-term arithmetic progression and no red arithmetic progression of length $e^{C(\\\\log N)^{3/4}(\\\\log \\\\log N)^{1/4}}$. Consequently, the two-colour van der Waerden number $w(3,k)$ is bounded below by $k^{b(k)}$, where $b(k) = c \\\\big ( \\\\frac {\\\\log k}{\\\\log \\\\log k} \\\\big )^{1/3}$. Previously it had been speculated, supported by data, that $w(3,k) = O(k^2)$.\",\"PeriodicalId\":56024,\"journal\":{\"name\":\"Forum of Mathematics Pi\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":2.8000,\"publicationDate\":\"2021-02-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Forum of Mathematics Pi\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.1017/fmp.2022.12\",\"RegionNum\":1,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Forum of Mathematics Pi","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1017/fmp.2022.12","RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
Abstract We show that there is a red-blue colouring of $[N]$ with no blue 3-term arithmetic progression and no red arithmetic progression of length $e^{C(\log N)^{3/4}(\log \log N)^{1/4}}$. Consequently, the two-colour van der Waerden number $w(3,k)$ is bounded below by $k^{b(k)}$, where $b(k) = c \big ( \frac {\log k}{\log \log k} \big )^{1/3}$. Previously it had been speculated, supported by data, that $w(3,k) = O(k^2)$.
期刊介绍:
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