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Related papers: On the $k$-limited packing numbers in graphs

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We study the Nordhaus-Gaddum type results for $(k-1,k,j)$ and $k$-domination numbers of a graph $G$ and investigate these bounds for the $k$-limited packing and $k$-total limited packing numbers in graphs. As the special case…

Combinatorics · Mathematics 2020-09-18 D. A. Mojdeh , Babak Samadi , Lutz Volkmann

In this paper, we find upper bounds on the open packing and $k$-limited packing numbers with emphasis on the cases $k=1$ and $k=2$. We solve the problem of characterizing all connected graphs on $n$ vertices with $\rho_{o}(G)=n/\delta(G)$…

Combinatorics · Mathematics 2019-08-27 D. A. Mojdeh , B. Samadi , A. Khodkar , H. R. Golmohammadi

A set $B$ of vertices in a graph $G$ is called a \emph{$k$-limited packing} if for each vertex $v$ of $G$, its closed neighbourhood has at most $k$ vertices in $B$. The \emph{$k$-limited packing number} of a graph $G$, denoted by $L_k(G)$,…

Combinatorics · Mathematics 2018-07-04 Xuqing Bai , Hong Chang , Xueliang Li

The upper and lower Nordhaus-Gaddum bounds over all graphs for the power domination number follow from known bounds on the domination number and examples. In this note we improve the upper sum bound for the power domination number…

In this paper, we study the domination number of middle graphs. Indeed, we obtain tight bounds for this number in terms of the order of the graph. We also compute the domination number of some families of graphs such as star graphs, double…

Combinatorics · Mathematics 2020-08-10 Farshad Kazemnejad , Behnaz Pahlavsay , Elisa Palezzato , Michele Torielli

In this paper, we study the signed domination numbers of graphs and present new sharp lower and upper bounds for this parameter. As an example, we present a lower bound on signed domination number of trees in terms of the order, leaves and…

Combinatorics · Mathematics 2019-08-27 S. M. Hosseini Moghaddam , Abdollah Khodkar , Babak Samadi

In this paper, we investigate the packing parameters in graphs. By applying the Mantel's theorem, We give upper bounds on packing and open packing numbers of triangle-free graphs along with characterizing the graphs for which the equalities…

Combinatorics · Mathematics 2019-08-27 D. A. Mojdeh , Babak Samadi

In this paper we study the weak Roman domination number and the secure domination number of a graph. In particular, we obtain general bounds on these two parameters and, as a consequence of the study, we derive new inequalities of…

Combinatorics · Mathematics 2020-08-04 Magdalena Valveny , Juan Alberto Rodriguez-Velazquez

In this paper, we study the signed total domination number in graphs and present new sharp lower and upper bounds for this parameter. For example by making use of the classic theorem of Turan, we present a sharp lower bound on this…

Combinatorics · Mathematics 2019-08-27 S. M. Hosseini Moghaddam , D. A. Mojdeh , Babak Samadi , L. Volkmann

A Nordhaus-Gaddum-type result is a (tight) lower or upper bound on the sum or product of a parameter of a graph and its complement. In this paper some variations are considered. First, recall their theorem, which gives bounds on the sum and…

Combinatorics · Mathematics 2014-09-23 Sunny Joseph Kalayathankal , Susanth C

Let $G$ be a graph, $S$ be a set of vertices of $G$, and $\lambda(S)$ be the maximum number $\ell$ of pairwise edge-disjoint trees $T_1, T_2,..., T_{\ell}$ in $G$ such that $S\subseteq V(T_i)$ for every $1\leq i\leq \ell$. The generalized…

Combinatorics · Mathematics 2013-01-01 Xueliang Li , Yaping Mao

The aim of this work is to investigate the nonnegative signed domination number $\gamma^{NN}_s$ with emphasis on regular, ($r+1$)-clique-free graphs and trees. We give lower and upper bounds on $\gamma^{NN}_s$ for regular graphs and prove…

Combinatorics · Mathematics 2018-09-25 Doost Ali Mojdeh , Babak Samadi , Lutz Volkmann

Graph packing generally deals with unlabeled graphs. In \cite{EHRT11}, the authors have introduced a new variant of the graph packing problem, called the \textit{labeled packing of a graph}. This problem has recently been studied on trees…

Discrete Mathematics · Computer Science 2014-11-03 M. A. Tahraoui , E. Duchene , H. Kheddouci , M. Wozniak

Let $G=(V,E)$ be a graph. For some $\alpha$ with $0<\alpha \leq 1$, a subset $S$ of $V$ is said to be a $\alpha$-partial dominating set if $|N[S]|\geq \alpha |V|$. The size of a smallest such $S$ is called the $\alpha$-partial domination…

Combinatorics · Mathematics 2021-11-09 Angsuman Das

In this paper we give tight upper bounds on the total domination number, the weakly connected domination number and the connected domination number of a graph in terms of order and Euler characteristic. We also present upper bounds for the…

Combinatorics · Mathematics 2013-10-08 Vladimir Samodivkin

In 2011, Henning, L\"{o}wenstein, and Rautenbach observed that the domination number of a graph is bounded from above by the product of the packing number and the maximum degree of the graph. We prove a stronger statement in subcubic…

Combinatorics · Mathematics 2023-07-12 Eun-Kyung Cho , Minki Kim

In this paper, we study the notions of connected domination number and of outer-connected domination number for middle graphs. Indeed, we obtain tight bounds for this number in terms of the order of the graph M(G). We also compute the…

Combinatorics · Mathematics 2022-07-01 Farshad Kazemnejad , Behnaz Pahlavsay , Elisa Palezzato , Michele Torielli

A dominating set in a graph $G$ is a set $S$ of vertices such that every vertex of $G$ is either in $S$ or is adjacent to a vertex in $S$. Nordhaus-Gaddum inequailties relate a graph $G$ to its complement $\bar{G}$. In this spirit Wagner…

Combinatorics · Mathematics 2019-10-30 Lauren Keough , David Shane

In this paper, we study the inverse signed total domination number in graphs and present new lower and upper bounds on this parameter. For example by making use of the classic theorem of Turan (1941), we present a sharp upper bound for…

Combinatorics · Mathematics 2019-08-27 D. A. Mojdeh , Babak Samadi

In this paper, we study the total outer-connected domination number of the middle graph of a simple graph and we obtain tight bounds for this number in terms of the order of the middle graph. We also compute the total outer-connected…

Combinatorics · Mathematics 2023-08-07 Farshad Kazemnejad , Behnaz Pahlavsay , Elisa Palezzato , Michele Torielli
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