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Related papers: Improved bounds for proper rainbow saturation

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A subgraph $H$ of an edge-colored graph $G$ is rainbow if all the edges of $H$ receive different colors. If $G$ does not contain a rainbow subgraph isomorphic to $H$, we say that $G$ is rainbow $H$-free. For connected graphs $H_1$ and…

Combinatorics · Mathematics 2025-02-04 Shun-ichi Maezawa , Akira Saito

An edge-coloured path is rainbow if its edges have distinct colours. For a connected graph $G$, the rainbow connection number (resp. strong rainbow connection number) of $G$ is the minimum number of colours required to colour the edges of…

Combinatorics · Mathematics 2017-11-06 Hui Lei , Henry Liu , Colton Magnant , Yongtang Shi

Let $c$ be an edge-coloring of the complete $n$-vertex graph $K_n$. The problem of finding properly colored and rainbow Hamilton cycles in $c$ was initiated in 1976 by Bollob\'as and Erd\H os and has been extensively studied since then.…

Combinatorics · Mathematics 2016-10-27 Nina Kamčev , Benny Sudakov , Jan Volec

The \emph{Tur\'an function} $\ex(n,F)$ of a graph $F$ is the maximum number of edges in an $F$-free graph with $n$ vertices. The classical results of Tur\'an and Rademacher from 1941 led to the study of supersaturated graphs where the key…

Combinatorics · Mathematics 2016-11-08 Oleg Pikhurko , Zelealem B. Yilma

A path in an edge-colored graph $G$, where adjacent edges may have the same color, is called rainbow if no two edges of the path are colored the same. The rainbow connection number $rc(G)$ of $G$ is the smallest integer $k$ for which there…

Combinatorics · Mathematics 2011-10-14 Hengzhe Li , Xueliang Li , Yuefang Sun

The oriented diameter of a bridgeless graph $G$ is $\min\{diam(H)\ | H\ is\ an orientation\ of\ G\}$. A path in an edge-colored graph $G$, where adjacent edges may have the same color, is called rainbow if no two edges of the path are…

Combinatorics · Mathematics 2011-12-06 Xiaolong Huang , Hengzhe Li , Xueliang Li , Yuefang Sun

Given a family of graphs $\mathcal{F}$, a graph $G$ is said to be $\mathcal{F}$-saturated if $G$ does not contain a copy of $F$ as a subgraph for any $F\in\mathcal{F}$, but the addition of any edge $e\notin E(G)$ creates at least one copy…

Combinatorics · Mathematics 2025-03-24 Yue Ma

An edge-colored graph is \emph{rainbow }if no two edges of the graph have the same color. An edge-colored graph $G^c$ is called \emph{properly colored} if every two adjacent edges of $G^c$ receive distinct colors in $G^c$. A \emph{strongly…

Combinatorics · Mathematics 2024-02-14 Peixue Zhao , Fei Huang

An edge-coloured graph $G$ is called $properly$ $connected$ if every two vertices are connected by a proper path. The $proper$ $connection$ $number$ of a connected graph $G$, denoted by $pc(G)$, is the smallest number of colours that are…

Combinatorics · Mathematics 2018-06-26 Xiaxia Guan , Lina Xue , Eddie Cheng , Weihua Yang

A proper total colouring of a graph $G$ is called harmonious if it has the further property that when replacing each unordered pair of incident vertices and edges with their colours, then no pair of colours appears twice. The smallest…

Combinatorics · Mathematics 2024-01-19 M. Abreu , J. B. Gauci , D. Mattiolo , G. Mazzuoccolo , F. Romaniello , C. Rubio-Montiel , T. Traetta

An edge-colored graph $G$ is rainbow connected if any two vertices are connected by a path whose edges have distinct colors. The rainbow connection number of $G$, denoted $rc(G)$, is the minimum number of colors that are used to make $G$…

Combinatorics · Mathematics 2010-12-15 Lily Chen , Xueliang Li , Huishu Lian

A path in an edge colored graph is said to be a rainbow path if no two edges on the path have the same color. An edge colored graph is (strongly) rainbow connected if there exists a (geodesic) rainbow path between every pair of vertices.…

Computational Complexity · Computer Science 2011-04-13 Prabhanjan Ananth , Meghana Nasre

A harmonious coloring of a $k$-uniform hypergraph $H$ is a vertex coloring such that no two vertices in the same edge have the same color, and each $k$-element subset of colors appears on at most one edge. The harmonious number $h(H)$ is…

Combinatorics · Mathematics 2024-08-07 Sebastian Czerwiński

This paper considers two important questions in the well-studied theory of graphs that are $F$-saturated. A graph $G$ is called $F$-saturated if $G$ does not contain a subgraph isomorphic to $F$, but the addition of any edge creates a copy…

Combinatorics · Mathematics 2020-07-17 Debsoumya Chakraborti , Po-Shen Loh

Given a graph $H$ and a positive integer $k$, the {\it $k$-colored Ramsey number} $R_k(H)$ is the minimum integer $n$ such that in every $k$-edge-coloring of the complete graph $K_{n}$, there is a monochromatic copy of $H$. Given two graphs…

Combinatorics · Mathematics 2025-11-07 Xihe Li , Xiangxiang Liu

A {\it 2-rainbow domination function} of a graph $G$ is a function $f$ that assigns to each vertex a set of colors chosen from the set $\{1,2\}$, such that for any $v\in V(G)$, $f(v)=\emptyset$ implies $\bigcup_{u\in N(v)}f(u)=\{1,2\}$. The…

Combinatorics · Mathematics 2010-05-07 Yunjian Wu , N. Jafari Rad

In this paper we show that for $r\geq 12$ and any sufficiently large $n$-vertex graph $G$ the number of $r$-edge-colorings of $G$ with no rainbow $K_4$ is at most $r^{ex(n,K_4)}$, where $ex(n,K_4)$ denotes the Tur\'{a}n number of $K_4$.…

Combinatorics · Mathematics 2025-05-02 Hiêp Hàn , Carlos Hoppen , Nicolas Moro Müller , Dionatan Ricardo Schmidt

For a given graph $F$, the $F$-saturation number of a graph $G$ is the minimum number of edges in an edge-maximal $F$-free subgraph of $G$. Recently, the $F$-saturation number of the Erd\H{o}s$\text{\bf--}$R\'enyi random graph…

Combinatorics · Mathematics 2017-09-26 A. Mohammadian , B. Tayfeh-Rezaie

Given an $n$-vertex graph $G$ with minimum degree at least $d n$ for some fixed $d > 0$, the distribution $G \cup \mathbb{G}(n,p)$ over the supergraphs of $G$ is referred to as a (random) {\sl perturbation} of $G$. We consider the…

Combinatorics · Mathematics 2020-04-21 Elad Aigner-Horev , Dan Hefetz

We study the following rainbow version of subgraph containment problems in a family of (hyper)graphs, which generalizes the classical subgraph containment problems in a single host graph. For a collection $\textbf{G}=\{G_1, G_2,\ldots,…

Combinatorics · Mathematics 2023-10-05 Yangyang Cheng , Jie Han , Bin Wang , Guanghui Wang
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