中文
相关论文

相关论文: A note on hypergraphs with asymmetric Ramsey prope…

200 篇论文

The size Ramsey number $ \hat{r}(G,H) $ of two graphs $ G $ and $ H $ is the smallest integer $ m $ such that there exists a graph $ F $ on $ m $ edges with the property that every red-blue colouring of the edges of $ F $, yields a red copy…

组合数学 · 数学 2016-09-14 Meysam Miralaei , Gholamreza Omidi , Maryam Shahsiah

Let $G_1, G_2, ..., G_t$ be graphs. The multicolor Ramsey number $R(G_1, G_2, ..., G_t)$ is the smallest positive integer $n$ such that if the edges of complete graph $K_n$ are partitioned into $t$ disjoint color classes giving $t$ graphs…

组合数学 · 数学 2012-07-17 Leila Maherani , Gholamreza Omidi , Ghaffar Raeisi , Maryam Shahsiah

A graph is $H$-Ramsey if every two-coloring of its edges contains a monochromatic copy of $H$. Define the $F$-Ramsey number of $H$, denoted by $r_F(H)$, to be the minimum number of copies of $F$ in a graph which is $H$-Ramsey. This…

组合数学 · 数学 2025-10-13 Jacob Fox , Jonathan Tidor , Shengtong Zhang

For given simple graphs $G_1$ and $G_2$, the size Ramsey number $\hat{R}(G_1,G_2)$ is the smallest positive integer $m$, where there exists a graph $G$ with $m$ edges such that in any edge coloring of $G$ with two colors red and blue, there…

组合数学 · 数学 2017-02-07 Ramin Javadi , Gholamreza Omidi

For two graphs, $G$ and $F$, and an integer $r\ge2$ we write $G\rightarrow (F)_r$ if every $r$-coloring of the edges of $G$ results in a monochromatic copy of $F$. In 1995, the first two authors established a threshold edge probability for…

组合数学 · 数学 2017-07-18 Vojtěch Rödl , Andrzej Ruciński , Mathias Schacht

An ordered graph $\mathcal{G}$ is a simple graph together with a total ordering on its vertices. The (2-color) Ramsey number of $\mathcal{G}$ is the smallest integer $N$ such that every 2-coloring of the edges of the complete ordered graph…

组合数学 · 数学 2019-02-26 Jesse Geneson , Amber Holmes , Xujun Liu , Dana Neidinger , Yanitsa Pehova , Isaac Wass

Let $mH$ be the graph formed by $m$ vertex-disjoint copies of a graph $H$. Let $G \to (H)_r$ denote that, in any $r$-colouring of the edges of $G$, there exists a monochromatic copy of $H$. In 1975, Burr, Erd\H{o}s, and Spencer showed that…

组合数学 · 数学 2026-05-21 Lucas Aragão , Xinbu Cheng , Rafael Filipe , Rafael Miyazaki , Danni Peng , Zhifei Yan

A celebrated result of R\"odl and Ruci\'nski states that for every graph $F$, which is not a forest of stars and paths of length $3$, and fixed number of colours $r\ge 2$ there exist positive constants $c, C$ such that for $p \leq…

The anti-Ramsey number $AR(n,G$), for a graph $G$ and an integer $n\geq|V(G)|$, is defined to be the minimal integer $r$ such that in any edge-colouring of $K_n$ by at least $r$ colours there is a multicoloured copy of $G$, namely, a copy…

组合数学 · 数学 2017-03-14 Arie Bialostocki , Shoni Gilboa , Yehuda Roditty

An edge-ordered graph is a graph with a linear ordering of its edges. Two edge-ordered graphs are equivalent if their is an isomorphism between them preserving the ordering of the edges. The edge-ordered Ramsey number $r_{edge}(H; q)$ of an…

组合数学 · 数学 2019-08-22 Jacob Fox , Ray Li

Let $r(G,H)$ be the smallest integer $N$ such that for any $2$-coloring (say, red and blue) of the edges of $K\_n$, $n\geqslant N$, there is either a red copy of $G$ or a blue copy of $H$. Let $K\_n-K\_{1,s}$ be the complete graph on $n$…

组合数学 · 数学 2016-04-01 Jonathan Chappelon , Luis Pedro Montejano , Jorge Ramírez Alfonsín

The Ramsey number $R(F,H)$ is the minimum number $N$ such that any $N$-vertex graph either contains a copy of $F$ or its complement contains $H$. Burr in 1981 proved a pleasingly general result that for any graph $H$, provided $n$ is…

组合数学 · 数学 2023-03-22 John Haslegrave , Joseph Hyde , Jaehoon Kim , Hong Liu

An $r$-regular graph is an $r$-graph, if every odd set of vertices is connected to its complement by at least $r$ edges. Let $G$ and $H$ be $r$-graphs. An $H$-coloring of $G$ is a mapping $f\colon E(G) \to E(H)$ such that each $r$ adjacent…

组合数学 · 数学 2023-05-16 Yulai Ma , Davide Mattiolo , Eckhard Steffen , Isaak H. Wolf

The Ramsey number $R(s,t)$ is the smallest integer $n$ such that all graphs of size $n$ contain a clique of size $s$ or an independent set of size $t$. $\mathcal{R}(s,t,n)$ is the set of all counterexample graphs without this property for a…

组合数学 · 数学 2024-11-28 Adam M. Lehavi

For graphs $F$ and $H$, we say $F$ is Ramsey for $H$ if every $2$-coloring of the edges of $F$ contains a monochromatic copy of $H$. The graph $F$ is Ramsey $H$-minimal if $F$ is Ramsey for $H$ and there is no proper subgraph $F'$ of $F$ so…

组合数学 · 数学 2023-02-01 Andrey Grinshpun , Raj Raina , Rik Sengupta

For fixed finite graphs $G$, $H$, a common problem in Ramsey theory is to study graphs $F$ such that $F \to (G,H)$, i.e. every red-blue coloring of the edges of $F$ produces either a red $G$ or a blue $H$. We generalize this study to…

组合数学 · 数学 2021-03-15 Jordan Mitchell Barrett , Valentino Vito

Given two graphs $G$ and $H$ and a positive integer $k$, the $k$-color Gallai-Ramsey number, denoted by $gr_{k}(G : H)$, is the minimum integer $N$ such that for all $n \geq N$, every $k$-coloring of the edges of $K_{n}$ contains either a…

组合数学 · 数学 2021-06-22 Zhao Wang , Yaping Mao , Colton Magnant , Ingo Sciermeyer , Jinyu Zou

The square $G^2$ of a graph $G$ is the graph on $V(G)$ with a pair of vertices $uv$ an edge whenever $u$ and $v$ have distance $1$ or $2$ in $G$. Given graphs $G$ and $H$, the Ramsey number $R(G,H)$ is the minimum $N$ such that whenever the…

组合数学 · 数学 2025-07-18 Peter Allen , Domenico Mergoni Cecchelli , Barnaby Roberts , Jozef Skokan

Given a pair of $k$-uniform hypergraphs $(G,H)$, the Ramsey number of $(G,H)$, denoted by $R(G,H)$, is the smallest integer $n$ such that in every red/blue-colouring of the edges of $K_n^{(k)}$ there exists a red copy of $G$ or a blue copy…

组合数学 · 数学 2024-06-25 Simona Boyadzhiyska , Allan Lo

For two graphs $G$ and $H$, the Ramsey number $r(G,H)$ is the smallest positive integer $r$, such that any red/blue coloring of the edges of the graph $K_r$ contains either a red subgraph that is isomorphic to $G$ or a blue subgraph that is…

组合数学 · 数学 2015-11-26 Sh. Haghi , H. R. Maimani , A. Seify