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Related papers: Chromatic Schultz Polynomial of Certain Graphs

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Let $G = (V,E)$ be a finite, simple, connected graph with chromatic polynomial $P_G(q)$. Sokal \cite{sokal} proved that the roots of the chromatic polynomial of $G$ are bounded in absolute value by $KD$ where, $D$ is the maximum degree of…

Combinatorics · Mathematics 2015-09-22 Sukhada Fadnavis

The distinguishing index of a graph $G$, denoted by $D'(G)$, is the least number of labels in an edge labeling of $G$ not preserved by any non-trivial automorphism. The distinguishing chromatic index $\chi'_D (G)$ of a graph $G$ is the…

Combinatorics · Mathematics 2017-12-12 Saeid Alikhani , Samaneh Soltani

Recall that the minimum number of colors that allow a proper coloring of graph $G$ is called the chromatic number of $G$ and denoted by $\chi(G).$ In this paper the concepts of $\chi$'-chromatic sum and $\chi^+$-chromatic sum are…

General Mathematics · Mathematics 2016-02-12 Johan Kok , Saptarshi Bej

Chromatic choosability is a notion of fundamental importance in list coloring. A graph $G$ is chromatic-choosable when its chromatic number, $\chi(G)$, is equal to its list chromatic number $\chi_{\ell}(G)$. In 1990, Kostochka and Sidorenko…

Combinatorics · Mathematics 2026-05-12 Yanghong Chi , Seoju Lee , Fennec Morrissette , Jeffrey A. Mudrock , Gavin Nguyen , Benjamin Whatley

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

The b-chromatic number of a graph G is the largest integer k such that G has a coloring of the vertices in k color classes such that every color class contains a vertex that has a neighbour in all other color classes. We characterize the…

Discrete Mathematics · Computer Science 2007-11-27 Frédéric Maffray , Meriem Mechebbek

Let $G$ be a $k$ - connected ($k \geq 2$) graph of order $n$. If $\chi(G) \geq n - k$, then $G$ is Hamiltonian or $K_k \vee (K_k^c \cup K_{n - 2k})$ with $n \geq 2 k + 1$, where $\chi(G)$ is the chromatic number of the graph $G$.

Combinatorics · Mathematics 2022-01-12 Rao Li

A new algorithm to obtain the chromatic number of a finite, connected graph is proposed in this paper. The algorithm is based on contraction of non adjacent vertices.

Discrete Mathematics · Computer Science 2019-10-16 Athma. M. Ram , R. Rama

Combinatorics, in particular graph theory, has a rich history of being a domain of successful applications of tools from other areas of mathematics, including topological methods. Here, we survey the study of the Hom-complexes, and the ways…

Algebraic Topology · Mathematics 2007-05-23 Dmitry N. Kozlov

The chromatic sum $\Sigma(G)$ of a graph $G$ is the smallest sum of colors among of proper coloring with the natural number. In this paper, we introduce a necessary condition for the existence of graph homomorphisms. Also, we present…

Combinatorics · Mathematics 2009-01-24 Meysam Alishahi , Ali Taherkhani

The chromatic symmetric function $X_G$ is a sum of monomials corresponding to proper vertex colorings of a graph $G$. Crew, Pechenik, and Spirkl (2023) recently introduced a $K$-theoretic analogue $\overline{X}_G$ called the Kromatic…

Combinatorics · Mathematics 2025-02-21 Laura Pierson

Let $G$ be a simple graph. A total dominator coloring of $G$ is a proper coloring of the vertices of $G$ in which each vertex of the graph is adjacent to every vertex of some color class. The total dominator chromatic number $\chi_d^t(G)$…

Combinatorics · Mathematics 2015-11-06 Saeid Alikhani , Nima Ghanbari

Sudoku grids can be thought of as graphs where the vertices are the squares of the grid, and edges join vertices in the same row, column, or sub-grid. A Sudoku puzzle corresponds to a partial proper coloring of the Sudoku graph. We provide…

Combinatorics · Mathematics 2008-07-02 Fusun Akman

A graph $G$ is \emph{chordless} if no cycle in $G$ has a chord. In the present work we investigate the chromatic index and total chromatic number of chordless graphs. We describe a known decomposition result for chordless graphs and use it…

Discrete Mathematics · Computer Science 2013-09-10 Raphael C. S. Machado , Celina M. H. de Figueiredo , Nicolas Trotignon

We introduce and study the dominated edge coloring of a graph. A dominated edge coloring of a graph $G$ is a proper edge coloring of $G$ such that each color class is dominated by at least one edge of $G$. The minimum number of colors among…

Combinatorics · Mathematics 2020-03-24 Mohammad R. Piri , Saeid Alikhani

The $k$th power $G^k$ of a graph $G$ is the graph defined on $V(G)$ such that two vertices $u$ and $v$ are adjacent in $G^k$ if the distance between $u$ and $v$ in $G$ is at most $k$. Let $\chi(H)$ and $\chi_l(H)$ be the chromatic number…

Combinatorics · Mathematics 2013-09-05 Seog-Jin Kim , Young Soo Kwon , Boram Park

Some important properties of the chromatic polynomial also hold for any polynomial set map satisfying p_S(x+y)=\sum_{T\uplus U=S}p_T(x)p_U(y). Using umbral calculus, we give a formula for the expansion of such a set map in terms of any…

Combinatorics · Mathematics 2007-07-06 Gus Wiseman

The chromatic polynomial $P(G,x)$ of a graph $G$ of order $n$ can be expressed as $\sum\limits_{i=1}^n(-1)^{n-i}a_{i}x^i$, where $a_i$ is interpreted as the number of broken-cycle free spanning subgraphs of $G$ with exactly $i$ components.…

Combinatorics · Mathematics 2020-08-12 Fengming Dong , Jun Ge , Helin Gong , Bo Ning , Zhangdong Ouyang , Eng Guan Tay

In this note we classify when a skew Schur function is a positive linear combination of power sum symmetric functions. We then use this to determine precisely when any scalar multiple of a skew Schur function is the chromatic symmetric…

Combinatorics · Mathematics 2018-09-03 Soojin Cho , Stephanie van Willigenburg

We use a well known concept of proper vertex colouring of a graph to introduce the construction of a chromatic completion graph and its related parameter, the chromatic completion number of a graph. We then give the chromatic completion…

General Mathematics · Mathematics 2018-09-06 E. G Mphako-Banda , J. Kok