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Related papers: The bipartite Ramsey numbers $BR(C_8, C_{2n})$

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While the problem of determining the representation number of an arbitrary word-representable graph is NP-hard, this problem is open even for bipartite graphs. The representation numbers are known for certain bipartite graphs including all…

Combinatorics · Mathematics 2025-06-03 Khyodeno Mozhui , K. V. Krishna

A Gallai $k$-coloring is a $k$-edge coloring of a complete graph in which there are no rainbow triangles. For two given graphs $H, G$ and two positive integers $k,s$ with that $s\leq k$, the $k$-colored Gallai-Ramsey number $gr_{k}(K_{3}:…

Combinatorics · Mathematics 2020-07-07 Xueli Su , Yan Liu

Given a positive integer $s$, the $s$-colour size-Ramsey number of a graph $H$ is the smallest integer $m$ such that there exists a graph $G$ with $m$ edges with the property that, in any colouring of $E(G)$ with $s$ colours, there is a…

Given two graphs $G$ and $H$, the $k$-colored Gallai-Ramsey number $gr_k(G : H)$ is defined to be the minimum integer $n$ such that every $k$-coloring of the complete graph on $n$ vertices contains either a rainbow copy of $G$ or a…

Combinatorics · Mathematics 2018-11-16 Xihe Li , Ligong Wang

We study Ramsey-type problems in Gallai-colorings. Given a graph $G$ and an integer $k\ge1$, the Gallai-Ramsey number $gr_k(K_3,G)$ is the least positive integer $n$ such that every $k$-coloring of the edges of the complete graph on $n$…

Combinatorics · Mathematics 2017-10-03 Christian Bosse , Zi-Xia Song

Given a graph $G$ and a positive integer $k$, define the \emph{Gallai-Ramsey number} to be the minimum number of vertices $n$ such that any $k$-edge coloring of the complete graph $K_n$ contains either a rainbow (all different colored)…

Combinatorics · Mathematics 2020-07-15 Yaping Mao , Zhao Wang , Colton Magnant , Ingo Sciermeyer

The $r$-size-Ramsey number $\hat{R}_r(H)$ of a graph $H$ is the smallest number of edges a graph $G$ can have, such that for every edge-coloring of $G$ with $r$ colors there exists a monochromatic copy of $H$ in $G$. For a graph $H$, we…

Combinatorics · Mathematics 2020-11-12 Nemanja Draganić , Michael Krivelevich , Rajko Nenadov

We say that a graph $G$ has the Ramsey property w.r.t.\ some graph $F$ and some integer $r\geq 2$, or $G$ is $(F,r)$-Ramsey for short, if any $r$-coloring of the edges of $G$ contains a monochromatic copy of $F$. R{\"o}dl and Ruci{\'n}ski…

Combinatorics · Mathematics 2018-02-16 Torsten Mütze , Ueli Peter

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…

Combinatorics · Mathematics 2021-06-22 Zhao Wang , Yaping Mao , Colton Magnant , Ingo Sciermeyer , Jinyu Zou

The Ramsey number $r(G)$ of a graph $G$ is the smallest integer $n$ such that any $2$ colouring of the edges of a clique on $n$ vertices contains a monochromatic copy of $G$. Determining the Ramsey number of $G$ is a central problem of…

Combinatorics · Mathematics 2023-02-02 Matija Bucic , Benny Sudakov

Let Q(n,c) denote the minimum clique size an n-vertex graph can have if its chromatic number is c. Using Ramsey graphs we give an exact, albeit implicit, formula for the case c is at least (n+3)/2.

Combinatorics · Mathematics 2012-04-11 Csaba Biró , Zoltán Füredi , Sogol Jahanbekam

We study quantitative aspects of the following fact: For every graph $F$, there exists a graph $G$ with the property that any $2$-coloring of the triangles of $G$ yields an induced copy of $F$, in which all triangles are monochromatic. We…

Combinatorics · Mathematics 2024-11-21 Ayush Basu , Vojtěch Rödl , Marcelo Sales

In his study of graph codes, Alon introduced the concept of the odd-Ramsey number of a family of graphs $\mathcal{H}$ in $K_n$, defined as the minimum number of colours needed to colour the edges of $K_n$ so that every copy of a graph $H\in…

Combinatorics · Mathematics 2024-10-10 Simona Boyadzhiyska , Shagnik Das , Thomas Lesgourgues , Kalina Petrova

Given a nonempty graph $G$, a collection of nonempty graphs $\cal{H}$, and a positive integer $k$, the Gallai-Ramsey number $\mathrm{gr}_k(G:\mathcal{H})$ is defined to be the minimum positive integer $n$ such that every exact…

Combinatorics · Mathematics 2026-01-21 Zhao Wang , Lanyanni Zhang , Meiqin Wei , Mark Budden

We say that a graph $F$ strongly arrows a pair of graphs $(G,H)$ if any 2-colouring of its edges with red and blue leads to either a red $G$ or a blue $H$ appearing as induced subgraphs of $F$. The induced Ramsey number, $IR(G,H)$ is…

Combinatorics · Mathematics 2017-10-30 Izolda Gorgol

For graphs $G$ and $H$, the Ramsey number $r(G,H)$ is the smallest positive integer $N$ such that any red/blue edge coloring of the complete graph $K_N$ contains either a red $G$ or a blue $H$. A book $B_n$ is a graph consisting of $n$…

Combinatorics · Mathematics 2024-01-26 Chunchao Fan , Qizhong Lin , Yuanhui Yan

Given a graph $H$ and an integer $k\ge1$, the Gallai-Ramsey number $GR_k(H)$ is defined to be the minimum integer $n$ such that every $k$-edge coloring of the complete graph $K_n$ contains either a rainbow (all different colored) triangle…

Combinatorics · Mathematics 2021-07-16 Qinghong Zhao , Bing Wei

Denote by $R(G_1, G_2, G_3)$ the minimum integer $N$ such that any three-colouring of the edges of the complete graph on $N$ vertices contains a monochromatic copy of a graph $G_i$ coloured with colour $i$ for some $i\in{1,2,3}$. In a…

Combinatorics · Mathematics 2015-08-31 David G. Ferguson

A Grundy k-coloring of a graph G, is a vertex k-coloring of G such that for each two colors i and j with i < j, every vertex of G colored by j has a neighbor with color i. The Grundy chromatic number (G), is the largest integer k for which…

Discrete Mathematics · Computer Science 2014-06-06 Ali Mansouri , Mohamed Salim Bouhlel

For graphs $F$ and $H$, the Ramsey number $R(F, H)$ is the smallest positive integer $N$ such that any red/blue edge coloring of $K_N$ contains either a red $F$ or a blue $H$. Let $C_n$ be a cycle of length $n$ and $F_n$ be a fan consisting…

Combinatorics · Mathematics 2022-10-26 Chunlin You , Qizhong Lin