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Related papers: On J-Colorability of Certain Derived Graph Classes

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We show that a graph class $\cal G$ has bounded expansion if and only if it has bounded $r$-neighbourhood complexity, i.e. for any vertex set $X$ of any subgraph $H$ of $G\in\cal G$, the number of subsets of $X$ which are exact…

Discrete Mathematics · Computer Science 2016-11-03 Felix Reidl , Fernando Sánchez Villaamil , Konstantinos Stavropoulos

For graph classes $P_1,...,P_k$, Generalized Graph Coloring is the problem of deciding whether the vertex set of a given graph $G$ can be partitioned into subsets $V_1,...,V_k$ so that $V_j$ induces a graph in the class $P_j$…

Combinatorics · Mathematics 2007-05-23 Vladimir E. Alekseev , Alastair Farrugia , Vadim V. Lozin

A coloring of the edges of a graph $G$ in which every $K_{1,2}$ is totally multicolored is known as a proper coloring and a coloring of the edges of $G$ in which every $K_{1,2}$ and every $K_{2,2}$ is totally multicolored is called a…

Combinatorics · Mathematics 2025-09-03 Ryan R. Martin , Miklós Ruszinkó , Gábor N. Sárközy

A graph is said to be interval colourable if it admits a proper edge-colouring using palette $\mathbb{N}$ in which the set of colours incident to each vertex is an interval. The interval colouring thickness of a graph $G$ is the minimum $k$…

A vertex-colored graph is {\it rainbow vertex-connected} if any two vertices are connected by a path whose internal vertices have distinct colors, which was introduced by Krivelevich and Yuster. The {\it rainbow vertex-connection} of a…

Combinatorics · Mathematics 2010-12-17 Xueliang Li , Yongtang Shi

Colouring the vertices of a graph $G$ according to certain conditions can be considered as a random experiment and a discrete random variable $X$ can be defined as the number of vertices having a particular colour in the proper colouring of…

General Mathematics · Mathematics 2017-06-09 N. K. Sudev , S. Satheesh , K. P. Chithra , Johan Kok

We consider vertex coloring of an acyclic digraph $\Gdag$ in such a way that two vertices which have a common ancestor in $\Gdag$ receive distinct colors. Such colorings arise in a natural way when bounding space for various genetic data…

Combinatorics · Mathematics 2007-06-12 Geir Agnarsson , Agust Egilsson , Magnus Mar Halldorsson

A (not necessarily proper) vertex coloring of a graph $G$ with color classes $V_1$, $V_2$, $\dots$, $V_k$, is said to be a {\it Fair And Tolerant vertex coloring of $G$ with $k$ colors}, whenever $V_1$, $V_2$, $\dots$, $V_k$ are nonempty…

Combinatorics · Mathematics 2025-11-25 Saeed Shaebani

If the vertices of a graph $G$ are colored with $k$ colors such that no adjacent vertices receive the same color and the sizes of any two color classes differ by at most one, then $G$ is said to be equitably $k$-colorable. Let $|G|$ denote…

Combinatorics · Mathematics 2014-08-27 Bor-Liang Chen , Kuo-Ching Huang , Ko-Wei Lih

The existence of a rainbow matching given a minimum color degree, proper coloring, or triangle-free host graph has been studied extensively. This paper, generalizes these problems to edge colored graphs with given total color degree. In…

Combinatorics · Mathematics 2019-07-09 J\''{u}rgen Kritschgau

In a colouring of a graph, a vertex is b-chromatic if it is adjacent to a vertex of every other colour. We consider four well-studied colouring problems: b-Chromatic Number, Tight b-Chromatic Number, Fall Chromatic Number and Fall…

Combinatorics · Mathematics 2026-05-07 Jungho Ahn , Tala Eagling-Vose , Felicia Lucke , David Manlove , Fabricio Mendoza , Daniël Paulusma

The $b$-chromatic number of a graph $G$, denoted by $b(G)$, is the largest positive integer $k$ such that there exists a proper coloring for G with $k$ colors in which every color class contains at least one vertex adjacent to some vertex…

Combinatorics · Mathematics 2013-02-19 Amine El Sahili , Hamamache Kheddouci , Mekkia Kouider , Miadoun Mortada

The study of graph vertex colorability from an algebraic perspective has introduced novel techniques and algorithms into the field. For instance, it is known that $k$-colorability of a graph $G$ is equivalent to the condition $1 \in…

Combinatorics · Mathematics 2007-09-24 Christopher J. Hillar , Troels Windfeldt

For a positive integer k and a graph G, we consider proper vertex-colourings of G with k colours in which all k colours are actually used. We call such a colouring a strong k-colouring. The strong k-colour graph of G, S_k(G), is the graph…

Combinatorics · Mathematics 2010-09-23 Somkiat Trakultraipruk

Given a proper edge coloring $\varphi$ of a graph $G$, we define the palette $S_{G}(v,\varphi)$ of a vertex $v \in V(G)$ as the set of all colors appearing on edges incident with $v$. The palette index $\check s(G)$ of $G$ is the minimum…

Combinatorics · Mathematics 2023-06-22 C. J. Casselgren , Petros A. Petrosyan

A vertex coloring of a given simple graph $G=(V,E)$ with $k$ colors ($k$-coloring) is a map from its vertex set to the set of integers $\{1,2,3,\dots, k\}$. A coloring is called perfect if the multiset of colors appearing on the neighbours…

Combinatorics · Mathematics 2020-05-29 O. G. Parshina , M. A. Lisitsyna

A proper edge-coloring of a graph $G$ with colors $1,\ldots,t$ is called an \emph{interval cyclic $t$-coloring} if all colors are used, and the edges incident to each vertex $v\in V(G)$ are colored by $d_{G}(v)$ consecutive colors modulo…

Combinatorics · Mathematics 2014-11-04 Petros A. Petrosyan , Sargis T. Mkhitaryan

We define a perfect coloring of a graph $G$ as a proper coloring of $G$ such that every connected induced subgraph $H$ of $G$ uses exactly $\omega(H)$ many colors where $\omega(H)$ is the clique number of $H$. A graph is perfectly colorable…

Combinatorics · Mathematics 2011-08-15 R B Sandeep

An edge coloring $c$ of a graph $G$ is a royal $k$-edge coloring of $G$ if the edges of $G$ are assigned nonempty subsets of the set $\{1, 2, \ldots, k\}$ in such a way that the vertex coloring obtained by assigning the union of the colors…

Combinatorics · Mathematics 2021-08-16 Akbar Ali , Gary Chartrand , James Hallas , Ping Zhang

An edge-colouring of a graph $G$ can fail to be rainbow for two reasons: either it contains a monochromatic cherry (a pair of incident edges), or a monochromatic matching of size two. A colouring is a proper colouring if it forbids the…

Combinatorics · Mathematics 2025-11-18 Allan Lo , Klas Markström , Dhruv Mubayi , Katherine Staden , Maya Stein , Lea Weber