English
Related papers

Related papers: Solutions for two conjectures on kaleidoscopic edg…

200 papers

A normal edge-coloring of a cubic graph is a proper edge-coloring, in which every edge is adjacent to edges colored with four distinct colors or to edges colored with two distinct colors. It is conjectured that $5$ colors suffice for a…

Combinatorics · Mathematics 2025-08-29 Igor Fabrici , Borut Lužar , Roman Soták , Diana Švecová

Consider edge colorings of digraphs where edges $v_1 v_2$ and $v_2 v_3$ have different colors. This coloring induces a vertex coloring by sets of edge colors, in which edge $v_1 v_2$ in the graph implies that the set color of $v_1$ contains…

Combinatorics · Mathematics 2024-07-10 Seth Chaiken

Given a graph $G$, a 2-coloring of the edges of $K_n$ is said to contain a balanced copy of $G$ if we can find a copy of $G$ such that half of its edges is in each color class. If there exists an integer $k$ such that, for $n$ sufficiently…

Combinatorics · Mathematics 2026-04-17 Antoine Dailly , Adriana Hansberg , Laura Eslava , Denae Ventura

A coloring is distinguishing (or symmetry breaking) if no non-identity automorphism preserves it. The distinguishing threshold of a graph $G$, denoted by $\theta(G)$, is the minimum number of colors $k$ so that every $k$-coloring of $G$ is…

Combinatorics · Mathematics 2022-12-19 Saeid Alikhani , Mohammad Hadi Shekarriz

Given an edge colouring of a graph with a set of $m$ colours, we say that the graph is (exactly) $m$-coloured if each of the colours is used. We consider edge colourings of the complete graph on $\mathbb{N}$ with infinitely many colours and…

Combinatorics · Mathematics 2016-09-07 Teeradej Kittipassorn , Bhargav Narayanan

A weighting of the edges of a hypergraph is called vertex-coloring if the weighted degrees of the vertices yield a proper coloring of the graph, i.e., every edge contains at least two vertices with different weighted degrees. In this paper…

Combinatorics · Mathematics 2016-05-20 Maciej Kalkowski , Michał Karoński , Florian Pfender

Let $G$ be a nontrivial connected graph of order $n$ with an edge-coloring $c:E(G)\rightarrow\{1,2,\dots,t\}$,$t\in\mathbb{N}$, where adjacent edges may be colored with the same color. A tree $T$ in $G$ is a \emph{proper tree} if no two…

Combinatorics · Mathematics 2016-12-07 Wenjing Li , Xueliang Li , Jingshu Zhang

A graph/multigraph $G$ is locally irregular if endvertices of every its edge possess different degrees. The locally irregular edge coloring of $G$ is its edge coloring with the property that every color induces a locally irregular…

Combinatorics · Mathematics 2024-10-04 Igor Grzelec , Tomáš Madaras , Alfréd Onderko , Roman Soták

The reconfiguration graph $\mathcal{C}_k(G)$ for the $k$-colourings of a graph $G$ has a vertex for each proper $k$-colouring of $G$, and two vertices of $\mathcal{C}_k(G)$ are adjacent precisely when those $k$-colourings differ on a single…

Combinatorics · Mathematics 2023-10-03 Stijn Cambie , Wouter Cames van Batenburg , Daniel W. Cranston

An edge-coloured cycle is rainbow if the edges have distinct colours. Let $G$ be a graph such that any $k$ vertices lie in a cycle of $G$. The $k$-rainbow cycle index of $G$, denoted by $crx_k(G)$, is the minimum number of colours required…

Combinatorics · Mathematics 2024-05-31 Henry Liu

For $k\ge 1$, we consider interleaved $k$-tuple colorings of the nodes of a graph, that is, assignments of $k$ distinct natural numbers to each node in such a way that nodes that are connected by an edge receive numbers that are strictly…

Combinatorics · Mathematics 2013-02-13 V. C. Barbosa

For a graph $G$ and a not necessarily proper $k$-edge coloring $c:E(G)\to \{ 1,\ldots,k\}$, let $m_i(G)$ be the number of edges of $G$ of color $i$, and call $G$ {\it color-balanced} if $m_i(G)=m_j(G)$ for every two colors $i$ and $j$.…

Combinatorics · Mathematics 2021-05-13 Johannes Pardey , Dieter Rautenbach

The chromatic polynomial $\pi_{G}(k)$ of a graph $G$ can be viewed as counting the number of vertices in a family of coloring graphs $\mathcal C_k(G)$ associated with (proper) $k$-colorings of $G$ as a function of the number of colors $k$.…

Combinatorics · Mathematics 2025-05-06 Shamil Asgarli , Sara Krehbiel , Howard W. Levinson , Heather M. Russell

A $k$-coloring of a graph is an assignment of integers between $1$ and $k$ to vertices in the graph such that the endpoints of each edge receive different numbers. We study a local variation of the coloring problem, which imposes further…

Combinatorics · Mathematics 2018-09-24 Jie You , Yixin Cao , Jianxin Wang

A path in an edge-colored graph $G$ is called monochromatic if any two edges on the path have the same color. For $k\geq 2$, an edge-colored graph $G$ is said to be monochromatic $k$-edge-connected if every two distinct vertices of $G$ are…

Combinatorics · Mathematics 2018-10-30 Ping Li , Xueliang Li

A conflict-free $k$-coloring of a graph $G=(V,E)$ assigns one of $k$ different colors to some of the vertices such that, for every vertex $v$, there is a color that is assigned to exactly one vertex among $v$ and $v$'s neighbors. Such…

Computational Geometry · Computer Science 2017-09-13 Sándor P. Fekete , Phillip Keldenich

A proper vertex $k$-coloring of a graph $G=(V,E)$ is an assignment $c:V\to \{1,2,\ldots,k\}$ of colors to the vertices of the graph such that no two adjacent vertices are associated with the same color. The square $G^2$ of a graph $G$ is…

Combinatorics · Mathematics 2019-02-22 Hervé Hocquard , Seog-Jin Kim , Théo Pierron

A $b$-coloring of a graph is a proper coloring such that every color class contains a vertex adjacent to at least one vertex in each of the other color classes. The $b$-chromatic number of a graph $G$, denoted by $b(G)$, is the maximum…

Combinatorics · Mathematics 2013-02-19 Amine El Sahili , Mekkia Kouider , Maidoun Mortada

An alternating cycle in a 2-two-edge-colored graph is a cycle such that any two consecutive edges have different colors. Let $G_1, \ldots, G_k$ be a collection of pairwise vertex disjoint 2-edge-colored graphs. The colored generalized sum…

Combinatorics · Mathematics 2019-10-07 Narda Cordero-Michel , Hortensia Galeana-Sánchez

Let $G$ be a graph whose each component has order at least 3. Let $s : E(G) \rightarrow \mathbb{Z}_k$ for some integer $k\geq 2$ be an improper edge coloring of $G$ (where adjacent edges may be assigned the same color). If the induced…

Discrete Mathematics · Computer Science 2016-09-26 Paniz Abedin , Saieed Akbari , Marc Demange , Tinaz Ekim