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An edge-colored graph is rainbow if all its edges are colored with distinct colors. For a fixed graph $H$, the rainbow Tur\'an number $\mathrm{ex}^{\ast}(n,H)$ is defined as the maximum number of edges in a properly edge-colored graph on…

Combinatorics · Mathematics 2012-05-15 Shagnik Das , Choongbum Lee , Benny Sudakov

The concept of rainbow disconnection number of graphs was introduced by Chartrand et al. in 2018. Inspired by this concept, we put forward the concepts of rainbow vertex-disconnection and proper disconnection in graphs. In this paper, we…

Combinatorics · Mathematics 2020-07-30 You Chen , Ping Li , Xueliang Li , Yindi Weng

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

An arc-coloured digraph $D$ is said to be \emph{rainbow connected} if for every two vertices $u$ and $v$ there is an $uv$-path all whose arcs have different colours. The minimun number of colours required to make the digraph rainbow…

Combinatorics · Mathematics 2015-04-28 Jesús Alva-Samos , Juan José Montellano-Ballesteros

Let $G$ be a finite group, the enhanced power graph of $G$, denoted by $\Gamma_G^e$, is the graph with vertex set $G$ and two vertices $x,y$ are edge connected in $\Gamma_{G}^e$ if there exist $z\in G$ such that $x,y\in\langle z\rangle$.…

Combinatorics · Mathematics 2017-08-28 Luis A. Dupont , Daniel G. Mendoza , Miriam Rodríguez

The rainbow number ${\rm rb}(G, H)$ is the minimum number of colors $k$ for which any edge-coloring of $G$ with at least $k$ colors guarantees a rainbow subgraph isomorphic to $H$. The rainbow number has many applications in diverse fields…

Combinatorics · Mathematics 2025-12-30 Mengyao Dai , Xin Zhang

Let $G$ be an edge colored graph. A {\it}{rainbow path} in $G$ is a path in which all the edges are colored with distinct colors. Let $d^c(v)$ be the color degree of a vertex $v$ in $G$, i.e. the number of distinct colors present on the…

Discrete Mathematics · Computer Science 2013-12-19 Anita Das , P. Suresh , S. V. Subrahmanya

In this paper, we study the connectivity of a one-dimensional soft random geometric graph (RGG). The graph is generated by placing points at random on a bounded line segment and connecting pairs of points with a probability that depends on…

Probability · Mathematics 2021-01-04 Michael Wilsher , Carl P. Dettmann , Ayalvadi Ganesh

A graph is said to be {\it total-colored} if all the edges and the vertices of the graph is colored. A path in a total-colored graph is a {\it total proper path} if $(i)$ any two adjacent edges on the path differ in color, $(ii)$ any two…

Combinatorics · Mathematics 2015-12-03 Hui Jiang , Xueliang Li , Yingying Zhang

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

Given a graph $H$, we say that a graph $G$ is properly rainbow $H$-saturated if: (1) There is a proper edge colouring of $G$ containing no rainbow copy of $H$; (2) For every $e \notin E(G)$, every proper edge colouring of $G+e$ contains a…

Combinatorics · Mathematics 2024-10-15 Andrew Lane , Natasha Morrison

Given a family of graphs $G_1,\dots,G_{n}$ on the same vertex set $[n]$, a rainbow Hamilton cycle is a Hamilton cycle on $[n]$ such that each $G_c$ contributes exactly one edge. We prove that if $G_1,\dots,G_{n}$ are independent samples of…

Combinatorics · Mathematics 2024-10-30 Asaf Ferber , Jie Han , Dingjia Mao

We introduce the algorithmic problem of finding a locally rainbow path of length $\ell$ connecting two distinguished vertices $s$ and $t$ in a vertex-colored directed graph. Herein, a path is locally rainbow if between any two visits of…

Data Structures and Algorithms · Computer Science 2024-02-21 Till Fluschnik , Leon Kellerhals , Malte Renken

Let $G$ be an edge-colored connected graph. A path $P$ in $G$ is called a distance $\ell$-proper path if no two edges of the same color appear with fewer than $\ell$ edges in between on $P$. The graph $G$ is called $(k,\ell)$-proper…

Combinatorics · Mathematics 2016-06-22 Xueliang Li , Colton Magnant , Meiqin Wei , Xiaoyu Zhu

In this paper, we generalize the concepts related to rainbow coloring to hypergraphs. Specifically, an $(n,r,H)$-local coloring is defined as a collection of $n$ edge-colorings, $f_v: E(K^{(r)}_n) \rightarrow [k]$ for each vertex $v$ in the…

Combinatorics · Mathematics 2025-05-13 Zhenyu Li , Weichan Liu , Guowei Sun , Xia Wang , Shunan Wei

We consider the Erd\H{o}s-R\'enyi random graph process, which is a stochastic process that starts with $n$ vertices and no edges, and at each step adds one new edge chosen uniformly at random from the set of missing edges. Let…

Combinatorics · Mathematics 2014-10-14 Deepak Bal , Patrick Bennett , Alan Frieze , Paweł Prałat

A conjecture of the first two authors is that $n$ matchings of size $n$ in any graph have a rainbow matching of size $n-1$. We prove a lower bound of $\frac{2}{3}n-1$, improving on the trivial $\frac{1}{2}n$, and an analogous result for…

Combinatorics · Mathematics 2021-10-08 Ron Aharoni , Eli Berger , Maria Chudnovsky , Shira Zerbib

Let $G = (V, E)$ be an $n$-vertex edge-colored graph. In 2013, H. Li proved that if every vertex $v \in V$ is incident to at least $(n+1)/2$ distinctly colored edges, then $G$ admits a rainbow triangle. We prove that the same hypothesis…

Combinatorics · Mathematics 2021-02-24 Andrzej Czygrinow , Theodore Molla , Brendan Nagle , Roy Oursler

We present an integer programming model to compute the strong rainbow connection number, $src(G)$, of any simple graph $G$. We introduce several enhancements to the proposed model, including a fast heuristic, and a variable elimination…

Combinatorics · Mathematics 2021-02-10 Logan A. Smith , David T. Mildebrath , Illya V. Hicks

Let $G = (V, E)$ be an $n$-vertex edge-colored graph. In 2013, H. Li proved that if every vertex $v \in V$ is incident to at least $(n+1)/2$ distinctly colored edges, then $G$ admits a rainbow triangle. We establish a corresponding result…

Combinatorics · Mathematics 2019-12-05 Andrzej Czygrinow , Theodore Molla , Brendan Nagle , Roy Oursler