{"title":"关于非对角线无序厄尔多斯-拉多数","authors":"Igor Araujo, Dadong Peng","doi":"arxiv-2409.11574","DOIUrl":null,"url":null,"abstract":"Erd\\H{o}s and Rado [P. Erd\\H{o}s, R. Rado, A combinatorial theorem, Journal\nof the London Mathematical Society 25 (4) (1950) 249-255] introduced the\nCanonical Ramsey numbers $\\text{er}(t)$ as the minimum number $n$ such that\nevery edge-coloring of the ordered complete graph $K_n$ contains either a\nmonochromatic, rainbow, upper lexical, or lower lexical clique of order $t$.\nRicher [D. Richer, Unordered canonical Ramsey numbers, Journal of Combinatorial\nTheory Series B 80 (2000) 172-177] introduced the unordered asymmetric version\nof the Canonical Ramsey numbers $\\text{CR}(s,r)$ as the minimum $n$ such that\nevery edge-coloring of the (unorderd) complete graph $K_n$ contains either a\nrainbow clique of order $r$, or an orderable clique of order $s$. We show that $\\text{CR}(s,r) = O(r^3/\\log r)^{s-2}$, which, up to the\nmultiplicative constant, matches the known lower bound and improves the\npreviously best known bound $\\text{CR}(s,r) = O(r^3/\\log r)^{s-1}$ by Jiang [T.\nJiang, Canonical Ramsey numbers and proporly colored cycles, Discrete\nMathematics 309 (2009) 4247-4252]. We also obtain bounds on the further variant\n$\\text{ER}(m,\\ell,r)$, defined as the minimum $n$ such that every edge-coloring\nof the (unorderd) complete graph $K_n$ contains either a monochromatic $K_m$,\nlexical $K_\\ell$, or rainbow $K_r$.","PeriodicalId":501407,"journal":{"name":"arXiv - MATH - Combinatorics","volume":"23 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"On the off-diagonal unordered Erdős-Rado numbers\",\"authors\":\"Igor Araujo, Dadong Peng\",\"doi\":\"arxiv-2409.11574\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Erd\\\\H{o}s and Rado [P. Erd\\\\H{o}s, R. Rado, A combinatorial theorem, Journal\\nof the London Mathematical Society 25 (4) (1950) 249-255] introduced the\\nCanonical Ramsey numbers $\\\\text{er}(t)$ as the minimum number $n$ such that\\nevery edge-coloring of the ordered complete graph $K_n$ contains either a\\nmonochromatic, rainbow, upper lexical, or lower lexical clique of order $t$.\\nRicher [D. Richer, Unordered canonical Ramsey numbers, Journal of Combinatorial\\nTheory Series B 80 (2000) 172-177] introduced the unordered asymmetric version\\nof the Canonical Ramsey numbers $\\\\text{CR}(s,r)$ as the minimum $n$ such that\\nevery edge-coloring of the (unorderd) complete graph $K_n$ contains either a\\nrainbow clique of order $r$, or an orderable clique of order $s$. We show that $\\\\text{CR}(s,r) = O(r^3/\\\\log r)^{s-2}$, which, up to the\\nmultiplicative constant, matches the known lower bound and improves the\\npreviously best known bound $\\\\text{CR}(s,r) = O(r^3/\\\\log r)^{s-1}$ by Jiang [T.\\nJiang, Canonical Ramsey numbers and proporly colored cycles, Discrete\\nMathematics 309 (2009) 4247-4252]. We also obtain bounds on the further variant\\n$\\\\text{ER}(m,\\\\ell,r)$, defined as the minimum $n$ such that every edge-coloring\\nof the (unorderd) complete graph $K_n$ contains either a monochromatic $K_m$,\\nlexical $K_\\\\ell$, or rainbow $K_r$.\",\"PeriodicalId\":501407,\"journal\":{\"name\":\"arXiv - MATH - Combinatorics\",\"volume\":\"23 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-09-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - MATH - Combinatorics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2409.11574\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - MATH - Combinatorics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2409.11574","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
Erd\H{o}s 和 Rado [P.Erd\H{o}s, R. Rado, A combinatorial theorem, Journalof the London Mathematical Society 25 (4) (1950) 249-255] 提出了典型拉姆齐数 $/text{er}(t)$,即有序完整图 $K_n$ 的每个边着色都包含阶数为 $t$ 的单色、彩虹、上词性或下词性簇的最小数 $n$ 。Richer [D. Richer, Unordered canonical Ramsey numbers, Journal of CombinatorialTheory Series B 80 (2000) 172-177] 引入了无序非对称版本的 Canonical Ramsey 数 $\text{CR}(s,r)$,即使得(无序的)完整图 $K_n$ 的每个边着色包含阶 $r$ 的彩虹簇或阶 $s$ 的可排序簇的最小值 $n$。我们证明,$\text{CR}(s,r) = O(r^3/\log r)^{s-2}$ 这个值(不含乘法常数)与已知的下界相匹配,并且改进了 Jiang [T.Jiang, Canonical Ramsey numbers and proporly colored cycles, DiscreteMathematics 309 (2009) 4247-4252] 所给出的已知最佳边界 $\text{CR}(s,r) = O(r^3//\log r)^{s-1}$。我们还得到了进一步变体$text{ER}(m,\ell,r)$ 的边界,其定义为:使(无序的)完整图 $K_n$ 的每个边着色都包含单色 $K_m$、词性 $K_\ell$ 或彩虹 $K_r$ 的最小值 $n$。
Erd\H{o}s and Rado [P. Erd\H{o}s, R. Rado, A combinatorial theorem, Journal
of the London Mathematical Society 25 (4) (1950) 249-255] introduced the
Canonical Ramsey numbers $\text{er}(t)$ as the minimum number $n$ such that
every edge-coloring of the ordered complete graph $K_n$ contains either a
monochromatic, rainbow, upper lexical, or lower lexical clique of order $t$.
Richer [D. Richer, Unordered canonical Ramsey numbers, Journal of Combinatorial
Theory Series B 80 (2000) 172-177] introduced the unordered asymmetric version
of the Canonical Ramsey numbers $\text{CR}(s,r)$ as the minimum $n$ such that
every edge-coloring of the (unorderd) complete graph $K_n$ contains either a
rainbow clique of order $r$, or an orderable clique of order $s$. We show that $\text{CR}(s,r) = O(r^3/\log r)^{s-2}$, which, up to the
multiplicative constant, matches the known lower bound and improves the
previously best known bound $\text{CR}(s,r) = O(r^3/\log r)^{s-1}$ by Jiang [T.
Jiang, Canonical Ramsey numbers and proporly colored cycles, Discrete
Mathematics 309 (2009) 4247-4252]. We also obtain bounds on the further variant
$\text{ER}(m,\ell,r)$, defined as the minimum $n$ such that every edge-coloring
of the (unorderd) complete graph $K_n$ contains either a monochromatic $K_m$,
lexical $K_\ell$, or rainbow $K_r$.