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Related papers: Strong coalitions in graphs

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\noindent A paired coalition in a graph $G=(V,E)$ consists of two disjoint sets of vertices $V_1$ and $V_2$, neither of which is a paired dominating set but whose union $V_1 \cup V_2$ is a paired dominating set. A paired coalition partition…

Combinatorics · Mathematics 2024-08-15 Mohammad Reza Samadzadeh , Doost Ali Mojdeh , Reza Nadimi

A set $D$ of vertices in a graph $G = (V, E)$ is a locating-dominating set (LD-set) if it is dominating and every two vertices $u$, $v$ of $V\setminus D$ satisfy $N(u) \cap D \neq N(v) \cap D$. Two disjoint sets $A,B\subset V(G)$ form a…

Combinatorics · Mathematics 2026-03-02 M. Chellali , A. A. Dobrynin , F. Foucaud , H. Golmohammadi , J. C. Valenzuela-Tripodoro

A set $S$ of vertices in a graph $G(V,E)$ is called a dominating set if every vertex $v\in V$ is either an element of $S$ or is adjacent to an element of $S$. A set $S$ of vertices in a graph $G(V,E)$ is called a total dominating set if…

Combinatorics · Mathematics 2008-10-28 Maryam Atapour , Nasrin Soltankhah

Let $G = (V,E)$ be a simple graph. A subset $S \subseteq V$ is called a $k$-fair dominating set if every vertex not in $S$ has exactly $k$ neighbors in $S$. Two disjoint sets $A, B \subseteq V$ form a $k$-fair coalition of $G$ if neither…

Combinatorics · Mathematics 2025-09-16 Abbas Jafari , Saeid Alikhani

Let $G=(V(G),E(G))$ be a simple graph. A set $D\subseteq V(G)$ is a strong dominating set of $G$, if for every vertex $x\in V(G)\setminus D$ there is a vertex $y\in D$ with $xy\in E(G)$ and $deg(x)\leq deg(y)$. The strong domination number…

Combinatorics · Mathematics 2022-10-21 Saeid Alikhani , Nima Ghanbari , Hassan Zaherifar

An independent coalition in a graph $G$ consists of two disjoint sets of vertices $V_1$ and $V_2$ neither of which is an independent dominating set but whose union $V_1 \cup V_2$ is an independent dominating set. An independent coalition…

Combinatorics · Mathematics 2024-07-29 Mohammad Reza Samadzadeh , Doost Ali Mojdeh

For a graph $G=(V,E)$, a pair of vertex disjoint sets $A_{1}$ and $A_{2}$ form a connected coalition of $G$, if $A_{1}\cup A_{2}$ is a connected dominating set, but neither $A_{1}$ nor $A_{2}$ is a connected dominating set. A connected…

Combinatorics · Mathematics 2024-02-02 Xiaxia Guan , Maoqun Wang

A set $S\subseteq V$ in an isolate-free graph $G$ is a total restrained dominating set, abbreviated TRD-set, if every vertex in $V$ is adjacent to a vertex in $S$, and every vertex in $V\setminus S$ is adjacent to a vertex in $V\setminus…

Combinatorics · Mathematics 2025-01-22 M. Chellali , J. C. Valenzuela-Tripodoro , H. Golmohammadi , I. I. Takhonov , N. A. Matrokhin

Let $G=(V,E)$ be a graph. A set $S\subseteq V(G)$ is a dominating set, if every vertex in $V(G)\backslash S$ is adjacent to at least one vertex in $S$. The $k$-dominating graph of $G$, $D_k (G)$, is defined to be the graph whose vertices…

Combinatorics · Mathematics 2015-03-02 Saeid Alikhani , Davood Fatehi

A dominating set of a graph $G$ is a set $D \subseteq V(G)$ such that every vertex in $V(G) \setminus D$ is adjacent to at least one vertex in $D$. A set $L\subseteq V(G)$ is a locating set of $G$ if every vertex in $V(G) \setminus L$ has…

Combinatorics · Mathematics 2026-04-17 Florent Foucaud , Paras Vinubhai Maniya , Kaustav Paul , Dinabandhu Pradhan

Let $G=(V,E)$ be a simple graph. A set $D\subseteq V$ is a strong dominating set of $G$, if for every vertex $x\in V\setminus D$ there is a vertex $y\in D$ with $xy\in E(G)$ and $deg(x)\leq deg(y)$. The strong domination number…

Combinatorics · Mathematics 2022-12-06 Saeid Alikhani , Nima Ghanbari

Let $G=\big{(}V(G),E(G)\big{)}$ be a graph with minimum degree $k$. A subset $S\subseteq V(G)$ is called a total $k$-dominating set if every vertex in $G$ has at least $k$ neighbors in $S$. Two disjoint sets $A,B\subset V(G)$ form a total…

Combinatorics · Mathematics 2025-12-10 Boštjan Brešar , Sandi Klavžar , Babak Samadi

In this paper, we propose and investigate the concept of $k$-coalitions in graphs, where $k\ge 1$ is an integer. A $k$-coalition refers to a pair of disjoint vertex sets that jointly constitute a $k$-dominating set of the graph, meaning…

Combinatorics · Mathematics 2024-07-15 Abbas Jafari , Saeid Alikhani , Davood Bakhshesh

Let $G=(V,E)$ be a simple graph. A set $D\subseteq V$ is a strong dominating set of $G$, if for every vertex $x\in V\setminus D$ there is a vertex $y\in D$ with $xy\in E(G)$ and $deg(x)\leq deg(y)$. The strong domination number…

Combinatorics · Mathematics 2023-02-03 Nima Ghanbari , Saeid Alikhani

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

Combinatorics · Mathematics 2022-11-15 Saieed Akbari , Nima Ghanbari , Michael A. Henning

For any graph~\(G,\) a set of vertices~\({\cal V}\) is said to be dominating if every vertex of~\(G\) contains at least one node of~\(G\) and separating if each vertex~\(v\) contains a unique neighbour~\(u_v \in {\cal V}\) that is adjacent…

Combinatorics · Mathematics 2021-08-17 Ghurumuruhan Ganesan

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

Combinatorics · Mathematics 2021-01-13 Nima Ghanbari , Saeid Alikhani

Let $\gamma(G)$ denote the domination number of a graph $G$. A vertex $v\in V(G)$ is called a \emph{critical vertex} of $G$ if $\gamma(G-v)=\gamma(G)-1$. A graph is called \emph{vertex-critical} if every vertex of it is critical. In this…

Combinatorics · Mathematics 2022-08-31 Weisheng Zhao , Ying Li , Ruizhi Lin

Haynes et al. (2020) introduced and investigated the concept of coalition in graphs \cite{hhhmm1}. Their study examined this concept from a vertex-based perspective, whereas in this paper, we extend the investigation to an edge-based…

Combinatorics · Mathematics 2025-07-29 Nazli Besharati , Azam Sadat Emadi , Iman Masoumi

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 $\gamma(G)$…