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Related papers: Zero Forcing in Claw-Free Cubic Graphs

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Let $G$ be a simple graph with maximum degree $\Delta(G)$ and chromatic index $\chi'(G)$. A classic result of Vizing indicates that either $\chi'(G )=\Delta(G)$ or $\chi'(G )=\Delta(G)+1$. The graph $G$ is called $\Delta$-critical if $G$ is…

Combinatorics · Mathematics 2018-05-17 Yan Cao , Guantao Chen , Guangming Jing , Songling Shan

A connected graph G is matching covered if every edge lies in some perfect matching of G. Lovasz proved that every matching covered graph G can be uniquely decomposed into a list of bricks (nonbipartite) and braces (bipartite) up to…

Combinatorics · Mathematics 2024-11-27 Yaxian Zhang , Fuliang Lu , Heping Zhang

A well known upper bound for the independence number $\alpha(G)$ of a graph $G$, is that \[ \alpha(G) \le n^0 + \min\{n^+ , n^-\}, \] where $(n^+, n^0, n^-)$ is the inertia of $G$. We prove that this bound is also an upper bound for the…

Combinatorics · Mathematics 2018-12-07 Pawel Wocjan , Clive Elphick

Zero forcing is a process on a graph in which the goal is to force all vertices to become blue by applying a color change rule. Throttling minimizes the sum of the number of vertices that are initially blue and the number of time steps…

Combinatorics · Mathematics 2019-03-15 Joshua Carlson

A zero forcing set is a set $S$ of vertices of a graph $G$, called forced vertices of $G$, which are able to force the entire graph by applying the following process iteratively: At any particular instance of time, if any forced vertex has…

Combinatorics · Mathematics 2023-06-22 Jessy Sujana G. , T. M. Rajalaxmi , Indra Rajasingh , R. Sundara Rajan

Given a family F of graphs, a graph G is F-free if it does not contain any graph in F as an induced subgraph. The problem of determining the complexity of colouring (claw, 4K1)- free graphs is a well-known open problem. In this paper we…

Combinatorics · Mathematics 2025-05-02 Kathie Cameron , Chính T. Hoàng , Taite LaGrange

For a fixed integer, the $k$-Colouring problem is to decide if the vertices of a graph can be coloured with at most $k$ colours for an integer $k$, such that no two adjacent vertices are coloured alike. A graph $G$ is $H$-free if $G$ does…

Combinatorics · Mathematics 2021-11-24 Barnaby Martin , Daniel Paulusma , Siani Smith

Probabilistic zero forcing is a graph coloring process in which blue vertices "infect" (color blue) white vertices with a probability proportional to the number of neighboring blue vertices. We introduce reversion probabilistic zero forcing…

Combinatorics · Mathematics 2024-04-24 Zachary Brennan

The boxicity (respectively cubicity) of a graph $G$ is the minimum non-negative integer $k$, such that $G$ can be represented as an intersection graph of axis-parallel $k$-dimensional boxes (respectively $k$-dimensional unit cubes) and is…

Combinatorics · Mathematics 2014-04-30 L. Sunil Chandran , Rogers Mathew , Deepak Rajendraprasad

Let $G$ be a graph and $\mathcal{F}$ a family of graphs. Define $\alpha_{\mathcal{F}}(G)$ as the maximum order of any induced subgraph of $G$ that belongs to the family $\mathcal{F}$. For the family $\mathcal{F}$ of graphs with…

Combinatorics · Mathematics 2026-05-12 Yair Caro , Randy Davila , Michael A. Henning , Ryan Pepper

Considering connected $K_{1,3}$-free graphs with independence number at least $3$, Chudnovsky and Seymour (2010) showed that every such graph, say $G$, is $2\omega$-colourable where $\omega$ denotes the clique number of $G$. We study…

Combinatorics · Mathematics 2019-03-25 Christoph Brause , Přemysl Holub , Adam Kabela , Zdeněk Ryjáček , Ingo Schiermeyer , Petr Vrána

A connected forcing set of a graph is a zero forcing set that induces a connected subgraph. In this paper, we introduce and study CF-dense graphs -- graphs in which every vertex belongs to some minimum connected forcing set. We identify…

Combinatorics · Mathematics 2025-07-16 Boris Brimkov , Randy Davila , Houston Schuerger

The maximum oriented $k$-forcing number of a simple graph $G$, written $\MOF_k(G)$, is the maximum directed $k$-forcing number among all orientations of $G$. This invariant was recently introduced by Caro, Davila and Pepper in…

Combinatorics · Mathematics 2017-09-25 Yair Caro , Ryan Pepper

Let $G$ be a bridgeless cubic graph. Consider a list of $k$ 1-factors of $G$. Let $E_i$ be the set of edges contained in precisely $i$ members of the $k$ 1-factors. Let $\mu_k(G)$ be the smallest $|E_0|$ over all lists of $k$ 1-factors of…

Combinatorics · Mathematics 2015-09-22 Eckhard Steffen

In this paper, we consider the following problem: given a connected graph $G$, can we reduce the domination number of $G$ by one by using only one edge contraction? We show that the problem is $\mathsf{NP}$-hard when restricted to…

Discrete Mathematics · Computer Science 2019-08-06 Esther Galby , Paloma T. Lima , Bernard Ries

Chung, Graham and Wilson defined a set of graphs $\mathcal{H}$ to be forcing, if any sequence of graphs $\{G_n\}_{n \geq 0}$ with $|G_n| = n$ must be quasirandom, whenever $hom(H, G_n)= (p^{|E(H)|}+o(1))n^{|V(H)|}$ for every $H \in…

Combinatorics · Mathematics 2023-12-12 Nikola Spasić

We consider vertex colorings of graphs in which adjacent vertices have distinct colors. A graph is $s$-chromatic if it is colorable in $s$ colors and any coloring of it uses at least $s$ colors. The forcing chromatic number $F(G)$ of an…

Computational Complexity · Computer Science 2007-05-23 Frank Harary , Wolfgang Slany , Oleg Verbitsky

For a non-decreasing positive integer sequence $S = (s_{1}, \dots, s_{k})$, an $S$-packing edge-coloring of a graph $G$ is a partition of the edge set of $G$ into subsets $E_{1}, \dots, E_{k}$ such that for each $1 \leq i \leq k$, the…

Combinatorics · Mathematics 2025-09-16 Jingxi Hou , Tao Wang , Xiaojing Yang

The forcing number of a graph with a perfect matching $M$ is the minimum number of edges in $M$ whose endpoints need to be deleted, such that the remaining graph only has a single perfect matching. This number is of great interest in…

Discrete Mathematics · Computer Science 2024-02-01 Maximilian Gorsky , Fabian Kreßin

In this paper, we first show that the power domination number of a connected $4$-regular claw-free graph on $n$ vertices is at most $\frac{n+1}{5}$, and the bound is sharp. The statement partly disprove the conjecture presented by Dorbec et…

Combinatorics · Mathematics 2018-08-09 Changhong Lu , Rui Mao , Bing Wang