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Related papers: A note on sub-total domination in graphs

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We propose the conjecture that the domination number $\gamma(G)$ of a $\Delta$-regular graph $G$ with $\Delta\geq 1$ is always at most its edge domination number $\gamma_e(G)$, which coincides with the domination number of its line graph.…

Combinatorics · Mathematics 2019-07-09 Julien Baste , Maximilian Fürst , Michael A. Henning , Elena Mohr , Dieter Rautenbach

In this paper, we investigate the relation between the (fractional) domination number of a digraph $G$ and the independence number of its underlying graph, denoted by $\alpha(G)$. More precisely, we prove that every digraph $G$ has…

Combinatorics · Mathematics 2018-04-30 Ararat Harutyunyan , Tien-Nam Le , Alantha Newman , Stéphan Thomassé

The {\em independent domination number} $\gamma^i(G)$ of a graph $G$ is the maximum, over all independent sets $I$, of the minimal number of vertices needed to dominate $I$. It is known \cite{abz} that in chordal graphs $\gamma^i$ is equal…

Combinatorics · Mathematics 2017-09-29 Ron Aharoni , Irina Gorelik

Given a graph G equals (V,E), a subset S subset of V is a dominating set if every vertex in V minus S is adjacent to some vertex in S. The dominating set with the least cardinality, gamma, is called a gamma-set which is commonly known as a…

Combinatorics · Mathematics 2026-01-01 Julian Allagan , Benkam Bobga

The domination number $\gamma(G)$ of a graph $G$, its exponential domination number $\gamma_e(G)$, and its porous exponential domination number $\gamma_e^*(G)$ satisfy $\gamma_e^*(G)\leq \gamma_e(G)\leq \gamma(G)$. We contribute results…

Combinatorics · Mathematics 2016-05-17 Michael A. Henning , Simon Jäger , Dieter Rautenbach

We prove that for every graph $G$ on $n$ vertices and with minimum degree five, the domination number $\gamma(G)$ cannot exceed $n/3$. The proof combines an algorithmic approach and the discharging method. Using the same technique, we…

Combinatorics · Mathematics 2020-05-18 Csilla Bujtás

For a graphical property $\mathcal{P}$ and a graph $G$, a subset $S$ of vertices of $G$ is a $\mathcal{P}$-set if the subgraph induced by $S$ has the property $\mathcal{P}$. The domination number with respect to the property $\mathcal{P}$,…

Combinatorics · Mathematics 2015-02-24 Vladimir Samodivkin

Let $G=(V,E)$ be a simple graph. A dominating set of $G$ is a subset $D\subseteq V$ such that every vertex not in $D$ is adjacent to at least one vertex in $D$. The cardinality of a smallest dominating set of $G$, denoted by $\gamma(G)$, is…

Combinatorics · Mathematics 2024-01-17 Nima Ghanbari , Saeid Alikhani , Mohammad Ali Dehghanizadeh

A sequence of vertices in a graph $G$ with no isolated vertices is called a total dominating sequence if every vertex in the sequence totally dominates at least one vertex that was not totally dominated by preceding vertices in the…

Combinatorics · Mathematics 2016-08-25 Boštjan Brešar , Tim Kos , Graciela Nasini , Pablo Torres

A set $D$ of vertices of a graph $G$ is a total dominating set if every vertex of $G$ is adjacent to at least one vertex of $D$. The total domination number of $G$ is the minimum cardinality of any total dominating set of $G$ and is denoted…

A dominating set of a graph $G$ is a subset $D \subseteq V_G$ such that every vertex not in $D$ is adjacent to at least one vertex in $D$. The cardinality of a smallest dominating set of $G$, denoted by $\gamma(G)$, is the domination number…

Combinatorics · Mathematics 2021-01-18 Joanna Cyman , Michael A. Henning , Jerzy Topp

Let $G_1$ and $G_2$ be disjoint copies of a graph $G$, and let $f: V(G_1) \rightarrow V(G_2)$ be a function. Then a \emph{functigraph} $C(G, f)=(V, E)$ has the vertex set $V=V(G_1) \cup V(G_2)$ and the edge set $E=E(G_1) \cup E(G_2) \cup…

Combinatorics · Mathematics 2012-04-17 Linda Eroh , Ralucca Gera , Cong X. Kang , Craig E. Larson , Eunjeong Yi

A set $D$ of vertices of a graph $G$ is a dominating set of $G$ if every vertex in $V_G-D$ is adjacent to at least one vertex in $D$. The domination number (upper domination number, respectively) of a graph $G$, denoted by $\gamma(G)$…

This paper initiates the study of fractional eternal domination in graphs, a natural relaxation of the well-studied eternal domination problem. We study the connections to flows and linear programming in order to obtain results on the…

Combinatorics · Mathematics 2023-04-25 Fnu Devvrit , Aaron Krim-Yee , Nithish Kumar , Gary MacGillivray , Ben Seamone , Virgélot Virgile , AnQi Xu

Let $G = (V, E)$ be a simple graph of order $n$. The total dominating set of $G$ is a subset $D$ of $V$ that every vertex of $V$ is adjacent to some vertices of $D$. The total domination number of $G$ is equal to minimum cardinality of…

Combinatorics · Mathematics 2019-10-15 Saeid Alikhani , Nasrin Jafari

The modular product $G\diamond H$ of graphs $G$ and $H$ is a graph on vertex set $V(G)\times V(H)$. Two vertices $(g,h)$ and $(g^{\prime},h^{\prime})$ of $G\diamond H$ are adjacent if $g=g^{\prime}$ and $hh^{\prime}\in E(H)$, or…

Combinatorics · Mathematics 2024-04-04 Sergio Bermudo , Iztok Peterin , Jelena Sedlar , Riste Škrekovski

This paper introduces the concept of compliant vertices and compliant graphs, with a focus on the total domination degree (TDD) of a vertex in compliant graphs. The TDD is systematically calculated for various graph classes, including path…

Combinatorics · Mathematics 2024-09-24 Kavya R. Nair , M. S. Sunitha

For a graph $G$ let $\gamma (G)$ be its domination number. We define a graph G to be (i) a hypo-efficient domination graph (or a hypo-$\mathcal{ED}$ graph) if $G$ has no efficient dominating set (EDS) but every graph formed by removing a…

Combinatorics · Mathematics 2016-01-12 Vladimir Samodivkin

Let $G=(V,E)$ be a graph. A subset $D$ of $V(G)$ is called a super dominating set if for every $v \in V(G)-D$ there exists an external private neighbour of $v$ with respect to $V(G)-D.$ The minimum cardinality of a super dominating set is…

Combinatorics · Mathematics 2013-09-06 M. Lemańska , V. Swaminathan , Y. B. Venkatakrishnan , R. Zuazua

Let $G$ be a connected graph of order $n$ with vertex set $V(G)$. A subset $S\subseteq V(G)$ is an $(a,b)$-dominating set if every vertex $v\in S$ is adjacent to at least $a$ vertices in $S$ and every $v\in V\setminus S$ is adjacent to at…

Combinatorics · Mathematics 2018-03-13 Sharareh Alipour , Amir Jafari