English
Related papers

Related papers: Anti-Ramsey numbers for paths

200 papers

The anti-Ramsey problem was introduced by Erd\H{o}s, Simonovits and S\'{o}s in 1970s. The anti-Ramsey number of a hypergraph $\mathcal{H}$, $ar(n,s, \mathcal{H})$, is the smallest integer $c$ such that in any coloring of the edges of the…

Combinatorics · Mathematics 2019-11-13 Ran Gu , Jiaao Li , Yongtang Shi

The anti-Ramsey numbers are a fundamental notion in graph theory, introduced in 1978, by Erd\" os, Simonovits and S\' os. For given graphs $G$ and $H$ the \emph{anti-Ramsey number} $\textrm{ar}(G,H)$ is defined to be the maximum number $k$…

Computational Complexity · Computer Science 2020-07-06 Saeed Akhoondian Amiri , Alexandru Popa , Mohammad Roghani , Golnoosh Shahkarami , Reza Soltani , Hossein Vahidi

The following relaxation of the classical problem of determining Ramsey number of a fixed graph has first been proposed by Erdos, Hajnal and Rado over 50 years ago. Given a graph $G$ and an integer $t \geq 2$ determine the minimum number…

Combinatorics · Mathematics 2021-06-29 Matija Bucić , Amir Khamseh

The study of ordered Ramsey numbers of monotone paths for graphs and hypergraphs has a long history, going back to the celebrated work by Erd\H{o}s and Szekeres in the early days of Ramsey theory. In this paper we obtain several results in…

Combinatorics · Mathematics 2023-08-09 Lior Gishboliner , Zhihan Jin , Benny Sudakov

Motivated by anti-Ramsey numbers introduced by Erd\H{o}s, Simonovits and S\'os in 1975, we study the anti-Ramsey problem when host graphs are plane triangulations. Given a positive integer $n$ and a planar graph $H$, let $\mathcal{T}_n(H)$…

Combinatorics · Mathematics 2017-12-07 Yongxin Lan , Yongtang Shi , Zi-Xia Song

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…

Combinatorics · Mathematics 2017-03-14 Arie Bialostocki , Shoni Gilboa , Yehuda Roditty

For given graphs $G$ and $H,$ the \emph{Ramsey number} $R(G,H)$ is the least natural number $n$ such that for every graph $F$ of order $n$ the following condition holds: either $F$ contains $G$ or the complement of $F$ contains $H.$ In this…

Combinatorics · Mathematics 2008-05-13 Kashif Ali , Edy Tri Baskoro , Ioan Tomescu

Given a graph $H$, the maximal anti-Ramsey function $f(n,e,H)$ denotes the minimum integer $f$ for which there exists an $n$-vertex graph $G$ with at least $e$ edges admitting an edge-coloring with $f$ colors in which each copy of $H$ in…

Combinatorics · Mathematics 2026-03-20 Matija Bucic , Kaizhe Chen , Jie Ma

For a fixed family of $r$-uniform hypergraphs $\mathcal{F}$, the anti-Ramsey number of $\mathcal{F}$, denoted by $ ar(n,r,\mathcal{F})$, is the minimum number $c$ of colors such that for any edge-coloring of the complete $r$-uniform…

Combinatorics · Mathematics 2024-05-08 Tong Li , Yucong Tang , Guanghui Wang , Guiying Yan

A formula concerning counting of paths was conjectured by Herzog and Conca few years ago. Recently, Krattenthaler and Prohaska gave an affirmative answer to this conjecture. In this paper we generalize this formula.

Commutative Algebra · Mathematics 2007-05-23 Hsin-Ju Wang

Let $H=(V,E)$ be an $r$-uniform hypergraph. For each $1 \leq s \leq r-1$, an $s$-path ${\mathcal P}^{r,s}_n$ of length $n$ in $H$ is a sequence of distinct vertices $v_1,v_2,\ldots,v_{s+n(r-s)}$ such that $\{v_{1+i(r-s)},\ldots,…

Combinatorics · Mathematics 2015-10-01 Xing Peng

In this paper arithmetic progressions on the integers and the integers modulo n are extended to graphs. This allows for the definition of the anti-van der Waerden number of a graph. Much of the focus of this paper is on 3-term arithmetic…

Recently, asymptotic values of 2-color Ramsey numbers for loose cycles and also loose paths were determined. Here we determine the 2-color Ramsey number of 3-uniform loose paths when one of the paths is significantly larger than the other:…

Combinatorics · Mathematics 2012-12-06 Leila Maherani , Gholamreza Omidi , Ghaffar Raeisi , Maryam Shahsiah

In 1980, Paul Erd\H{o}s posed the following problem: For every positive integer $n,$ determine a nonhamiltonian graph of order $n$ having the maximum number of Hamilton paths. We solve the more general problem of determining the…

Combinatorics · Mathematics 2026-05-27 Chengli Li , Xingzhi Zhan

We show that for any natural number $k \ge 1$, any oriented graph $D$ of minimum semidegree at least $(3k- 2)/4$ contains an antidirected path of length $k$. In fact, a slightly weaker condition on the semidegree sequence of $D$ suffices,…

Combinatorics · Mathematics 2024-02-07 Tereza Klimošová , Maya Stein

Gy\'{a}rf\'{a}s et al. determined the asymptotic value of the diagonal Ramsey number of $\mathcal{C}^k_n$, $R(\mathcal{C}^k_n,\mathcal{C}^k_n),$ generating the same result for $k=3$ due to Haxell et al. Recently, the exact values of the…

Combinatorics · Mathematics 2018-06-21 Maryam Shahsiah

Let $G_1$ and $G_2$ be two given graphs. The Ramsey number $R(G_1,G_2)$ is the least integer $r$ such that for every graph $G$ on $r$ vertices, either $G$ contains a $G_1$ or $\overline{G}$ contains a $G_2$. We denote by $P_n$ the path on…

Combinatorics · Mathematics 2016-06-21 Binlong Li , Bo Ning

For given graphs $G$ and $H,$ the \emph{Ramsey number} $R(G,H)$ is the least natural number $n$ such that for every graph $F$ of order $n$ the following condition holds: either $F$ contains $G$ or the complement of $F$ contains $H.$ In this…

Combinatorics · Mathematics 2007-11-19 Kashif Ali , Edy Tri Baskoro

An oriented graph is called $k$-anti-traceable if the subdigraph induced by every subset with $k$ vertices has a hamiltonian anti-directed path. In this paper, we consider an anti-traceability conjecture. In particular, we confirm this…

Combinatorics · Mathematics 2024-03-29 Bin Chen , Stefanie Gerke , Gregory Gutin , Hui Lei , Heis Parker-Cox , Yacong Zhou

We prove that for every $k\ge 10$, the online Ramsey number for paths $P_k$ and $P_n$ satisfies $\tilde{r}(P_k,P_n) \geq \frac{5}{3}n + \frac{k}{9} - 4$, matching up to a linear term in $k$ the upper bound recently obtained by…

Combinatorics · Mathematics 2024-08-13 Adva Mond , Julien Portier
‹ Prev 1 2 3 10 Next ›