English
Related papers

Related papers: On r-dynamic Coloring of Grids

200 papers

A star coloring of a graph $G$ is a proper vertex coloring such that the subgraph induced by any pair of color classes is a star forest. The star chromatic number of $G$ is the minimum number of colors needed to star color $G$. In this…

Combinatorics · Mathematics 2017-10-12 Sumun Iyer

A \textit{star $k$-coloring} of a graph $G$ is a proper (vertex) $k$-coloring of $G$ such that the vertices on a path of length three receive at least three colors. Given a graph $G$, its \textit{star chromatic number}, denoted $\chi_s(G)$,…

Combinatorics · Mathematics 2019-09-26 Ilkyoo Choi , Boram Park

The strong chromatic number $\chi_{\text{s}}(G)$ of a graph $G$ on $n$ vertices is the least number $r$ with the following property: after adding $r \lceil n/r \rceil - n$ isolated vertices to $G$ and taking the union with any collection of…

Combinatorics · Mathematics 2019-08-15 Allan Lo , Nicolás Sanhueza-Matamala

It is proved that every connected graph $G$ on $n$ vertices with $\chi(G) \geq 4$ has at most $k(k-1)^{n-3}(k-2)(k-3)$ $k$-colourings for every $k \geq 4$. Equality holds for some (and then for every) $k$ if and only if the graph is formed…

Combinatorics · Mathematics 2017-08-08 Fiachra Knox , Bojan Mohar

An $n$-subdivision of a graph $G$ is a graph constructed by replacing a path of length $n$ instead of each edge of $G$ and an $m$-power of $G$ is a graph with the same vertices as $G$ and any two vertices of $G$ at distance at most $m$ are…

Combinatorics · Mathematics 2022-05-17 Mahsa Mozafari-Nia , Moharram N. Iradmusa

Let $H=(V(H),E(H))$ be a graph. A $k$-coloring of $H$ is a mapping $\pi : V(H) \longrightarrow \{1,2,\ldots, k\}$ so that each color class induces a $K_2$-free subgraph. For a graph $G$ of order at least $2$, a $G$-free $k$-coloring of $H$…

Combinatorics · Mathematics 2022-01-21 Yaser Rowshan

A 2-distance $k$-coloring of a graph $G$ is a proper $k$-coloring such that any two vertices at distance two or less get different colors. The 2-distance chromatic number of $G$ is the minimum $k$ such that $G$ has a 2-distance…

Combinatorics · Mathematics 2024-06-26 Kengo Aoki

A proper vertex coloring of a graph is equitable if the sizes of color classes differ by at most 1. The equitable chromatic number of a graph $G$, denoted by $\chi_=(G)$, is the minimum $k$ such that $G$ is equitably $k$-colorable. The…

Combinatorics · Mathematics 2012-10-02 Zhidan Yan , Wei Wang

The chromatic number of a graph is the minimum $k$ such that the graph has a proper $k$-coloring. There are many coloring parameters in the literature that are proper colorings that also forbid bicolored subgraphs. Some examples are…

Combinatorics · Mathematics 2018-12-05 Ilkyoo Choi , Ringi Kim , Boram Park

A graceful $l$-coloring of a graph $G$ is a proper vertex coloring with $l$ colors which induces a proper edge coloring with at most $l-1$ colors, where the color for an edge $ab$ is the absolute difference between the colors assigned to…

Combinatorics · Mathematics 2024-07-01 Laavanya D. , Devi Yamini S.

\noindent Let $G$ be a simple graph. For any $k\in N$, the $k-$power of $G$ is a simple graph $G^k$ with vertex set $V(G)$ and edge set $\{xy:d_G(x,y)\leq k\}$ and the $k-$subdivision of $G$ is a simple graph $G^{\frac{1}{k}}$, which is…

Combinatorics · Mathematics 2009-02-13 Moharram N. Iradmusa

A \emph{dynamic colouring} of a graph is a proper colouring in which no neighbourhood of a non-leaf vertex is monochromatic. The \emph{dynamic colouring number} $\chi_2(G)$ of a graph $G$ is the least number of colours needed for a dynamic…

Combinatorics · Mathematics 2017-02-06 Nathan Bowler , Joshua Erde , Florian Lehner , Martin Merker , Max Pitz , Konstantinos Stavropoulos

A strong $k$-edge-coloring of a graph G is an edge-coloring with $k$ colors in which every color class is an induced matching. The strong chromatic index of $G$, denoted by $\chi'_{s}(G)$, is the minimum $k$ for which $G$ has a strong…

Combinatorics · Mathematics 2018-09-11 Tianjiao Dai , Guanghui Wang , Donglei Yang , Gexin Yu

The star chromatic index of a multigraph $G$, denoted $\chi'_{s}(G)$, is the minimum number of colors needed to properly color the edges of $G$ such that no path or cycle of length four is bi-colored. A multigraph $G$ is star…

Combinatorics · Mathematics 2017-11-23 Hui Lei , Yongtang Shi , Zi-Xia Song

A $k$-star colouring of a graph $G$ is a function $f:V(G)\to\{0,1,\dots,k-1\}$ such that $f(u)\neq f(v)$ for every edge $uv$ of $G$, and every bicoloured connected subgraph of $G$ is a star. The star chromatic number of $G$, $\chi_s(G)$, is…

Combinatorics · Mathematics 2023-09-11 Shalu M. A. , Cyriac Antony

A vertex coloring of a graph $G$ is called distinguishing if no non-identity automorphisms of $G$ can preserve it. The distinguishing number of $G$, denoted by $D(G)$, is the minimum number of colors required for such a coloring, and the…

A proper edge coloring of a graph $G$ is called acyclic if there is no bichromatic cycle in $G$. The acyclic chromatic index of $G$, denoted by $\chi'_a(G)$, is the least number of colors $k$ such that $G$ has an acyclic edge $k$-coloring.…

Combinatorics · Mathematics 2015-03-13 Jianfeng Hou

The proper chromatic number $\Vec{\chi}(G)$ of a graph $G$ is the minimum $k$ such that there exists an orientation of the edges of $G$ with all vertex-outdegrees at most $k$ and such that for any adjacent vertices, the outdegrees are…

Combinatorics · Mathematics 2022-12-09 Yaobin Chen , Bojan Mohar , Hehui Wu

The mutual-visibility chromatic number of a graph $G$ is the smallest number of colors needed to color the vertices of $G$ such that each color class is a mutual-visibility set. In this paper, we prove that determining the mutual-visibility…

Combinatorics · Mathematics 2026-02-13 Saneesh Babu , Gabriele Di Stefano , Aparna Lakshmanan S

We prove that for any graph $G$, the total chromatic number of $G$ is at most $\Delta(G)+2\left\lceil \frac{|V(G)|}{\Delta(G)+1} \right\rceil$. This saves one color in comparison with a result of Hind from 1992. In particular, our result…

Combinatorics · Mathematics 2024-05-14 Aseem Dalal , Jessica McDonald , Songling Shan