English
Related papers

Related papers: A sharp upper bound for the rainbow 2-connection n…

200 papers

An edge-colored graph $G$ is conflict-free connected if any two of its vertices are connected by a path which contains a color used on exactly one of its edges. The conflict-free connection number of a connected graph $G$, denoted by…

Combinatorics · Mathematics 2018-09-12 Ran Gu , Xueliang Li

A tree in an edge-colored graph $G$ is said to be a rainbow tree if no two edges on the tree share the same color. Given two positive integers $k$, $\ell$ with $k\geq 3$, the \emph{$(k,\ell)$-rainbow index} $rx_{k,\ell}(G)$ of $G$ is the…

Combinatorics · Mathematics 2013-10-21 Qingqiong Cai , Xueliang Li , Jiangli Song

The concept of $k$-rainbow index $rx_k(G)$ of a connected graph $G$, introduced by Chartrand, Okamoto and Zhang, is a natural generalization of the rainbow connection number. Let $t(n,k,\ell)$ denote the minimum size of a connected graph…

Combinatorics · Mathematics 2015-09-28 Thomas Y. H. Liu

An edge-colored graph is called \textit{rainbow graph} if all the colors on its edges are distinct. Given a positive integer $n$ and a graph $G$, the \textit{anti-Ramsey number} $ar(n,G)$ is defined to be the minimum number of colors $r$…

Combinatorics · Mathematics 2025-06-10 Hongliang Lu , Xinyue Luo , Xinxin Ma

Given a family $\mathcal G$ of graphs on a common vertex set $X$, we say that $\mathcal G$ is rainbow connected if for every vertex pair $u,v \in X$, there exists a path from $u$ to $v$ that uses at most one edge from each graph in…

Combinatorics · Mathematics 2021-07-15 Peter Bradshaw , Bojan Mohar

An edge-coloured cycle is $rainbow$ if all edges of the cycle have distinct colours. For $k\geq 1$, let $\mathcal{F}_{k}$ denote the family of all graphs with the property that any $k$ vertices lie on a cycle. For $G\in \mathcal{F}_{k}$, a…

Combinatorics · Mathematics 2018-10-09 Shasha Li , Yongtang Shi , Jianhua Tu , Yan Zhao

In this paper we consider properly edge-colored graphs, i.e. two edges with the same color cannot share an endpoint, so each color class is a matching. A matching is called \it rainbow \rm if its edges have different colors. The minimum…

Combinatorics · Mathematics 2012-08-29 Andras Gyarfas , Gabor N. Sarkozy

The rainbow connection number $rc(G)$ and the rainbow vertex-connection number $rvc(G)$ of a graph $G$ were introduced by Chartrand et al. and Krivelevich and Yuster, respectively. Good upper bounds in terms of minimum degree $\delta$ were…

Combinatorics · Mathematics 2011-03-22 Jiuying Dong , Xueliang Li

An edge-colored connected graph $G$ is properly connected if between every pair of distinct vertices, there exists a path that no two adjacent edges have a same color. Fujita (2019) introduced the optimal proper connection number…

Combinatorics · Mathematics 2020-03-20 Shinya Fujita , Boram Park

A rainbow matching in an edge-colored graph is a matching in which no two edges have the same color. The color degree of a vertex v is the number of different colors on edges incident to v. Kritschgau [Electron. J. Combin. 27(2020)] studied…

Combinatorics · Mathematics 2021-05-25 Wenling Zhou

An edge-coloured path is \emph{rainbow} if its edges have distinct colours. An edge-coloured connected graph is said to be \emph{rainbow connected} if any two vertices are connected by a rainbow path, and \emph{strongly rainbow connected}…

Combinatorics · Mathematics 2017-07-18 Hui Lei , Shasha Li , Henry Liu , Yongtang Shi

Let $G$ be an edge-coloured graph. The minimum colour degree $\delta^c(G)$ of $G$ is the largest integer $k$ such that, for every vertex $v$, there are at least $k$ distinct colours on edges incident to $v$. We say that $G$ is properly…

Combinatorics · Mathematics 2018-08-14 Allan Lo

A path in an edge-colored graph is called a rainbow path if every two distinct edges of the path have different colors. A graph whose every pair of vertices are linked by a rainbow path is called a rainbow-connected graph. The rainbow…

Combinatorics · Mathematics 2024-10-29 Rian Febrian Umbara , A. N. M. Salman , Pritta Etriana Putri

Given an edge-colored graph $G$, we denote the number of colors as $c(G)$, and the number of edges as $e(G)$. An edge-colored graph is rainbow if no two edges share the same color. A proper $mK_3$ is a vertex disjoint union of $m$ rainbow…

Combinatorics · Mathematics 2024-02-29 Jürgen Kritschgau , tahda queer , Cyrus Young , Wohua Zhou

For an edge-colored graph $G$, we call an edge-cut $M$ of $G$ monochromatic if the edges of $M$ are colored with the same color. The graph $G$ is called monochromatic disconnected if any two distinct vertices of $G$ are separated by a…

Combinatorics · Mathematics 2020-09-07 Ping Li , Xueliang Li

Given an edge-coloured graph, we say that a subgraph is rainbow if all of its edges have different colours. Let $\operatorname{ex}(n,H,$rainbow-$F)$ denote the maximal number of copies of $H$ that a properly edge-coloured graph on $n$…

Combinatorics · Mathematics 2022-02-28 Barnabás Janzer

For a connected graph, we define the proper-walk connection number as the minimum number of colors needed to color the edges of a graph so that there is a walk between every pair of vertices without two consecutive edges having the same…

Combinatorics · Mathematics 2017-04-25 Robert Melville , Wayne Goddard

Let $G$ be an edge-colored graph on $n$ vertices. For a vertex $v$, the \emph{color degree} of $v$ in $G$, denoted by $d^c(v)$, is the number of colors appearing on the edges incident with $v$. Denote by $\delta^c(G)=\min\{d^c(v):v\in…

Combinatorics · Mathematics 2025-10-14 Xiaozheng Chen , Bo Ning

For a graph with colored vertices, a rainbow subgraph is one where all vertices have different colors. For graph $G$, let $c_k(G)$ denote the maximum number of different colors in a coloring without a rainbow path on $k$ vertices, and…

Combinatorics · Mathematics 2025-01-03 Wayne Goddard , Tyler Herrman , Simon J. Hughes

A tree $T$, in an edge-colored graph $G$, is called {\em a rainbow tree} if no two edges of $T$ are assigned the same color. A {\em $k$-rainbow coloring}of $G$ is an edge coloring of $G$ having the property that for every set $S$ of $k$…

Combinatorics · Mathematics 2014-03-05 Tingting Liu , Yumei Hu