3,755 research outputs found
On Roman, Global and Restrained Domination in Graphs
In this paper, we present new upper bounds for the global domination and Roman domination numbers and also prove that these results are asymptotically best possible. Moreover, we give upper bounds for the restrained domination and total restrained domination numbers for large classes of graphs, and show that, for almost all graphs, the restrained domination number is equal to the domination number, and the total restrained domination number is equal to the total domination number. A number of open problems are posed. © 2010 Springer
Integer Programming Formulations and Probabilistic Bounds for Some Domination Parameters
In this paper, we further study the concepts of hop domination and 2-step
domination and introduce the concepts of restrained hop domination, total
restrained hop domination, 2-step restrained domination, and total 2-step
restrained domination in graphs. We then construct integer programming
formulations and present probabilistic upper bounds for these domination
parameters
Remarks on restrained domination and total restrained domination in graphs
summary:The restrained domination number and the total restrained domination number of a graph were introduced recently by various authors as certain variants of the domination number of . A well-known numerical invariant of a graph is the domatic number which is in a certain way related (and may be called dual) to . The paper tries to define analogous concepts also for the restrained domination and the total restrained domination and discusses the sense of such new definitions
Upper bounds for domination related parameters in graphs on surfaces
AbstractIn 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 restrained bondage number, the total restrained bondage number and the restricted edge connectivity of graphs in terms of the orientable/nonorientable genus and maximum degree
Remarks on restrained domination and total restrained domination in graphs
The restrained domination number γ r(G) and the total restrained domination number γ t r (G) of a graph G were introduced recently by various authors as certain variants of the domination number γ(G) of (G). A well-known numerical invariant of a graph is the domatic number d(G) which is in a certain way related (and may be called dual) to γ(G). The paper tries to define analogous concepts also for the restrained domination and the total restrained domination and discusses the sense of such new definitions. © Mathematical Institute, Academy of Sciences of Czech Republic 2005
Characterizations in Domination Theory
Let G = (V,E) be a graph. A set R is a restrained dominating set (total restrained dominating set, resp.) if every vertex in V − R (V) is adjacent to a vertex in R and (every vertex in V −R) to a vertex in V −R. The restrained domination number of G (total restrained domination number of G), denoted by gamma_r(G) (gamma_tr(G)), is the smallest cardinality of a restrained dominating set (total restrained dominating set) of G. If T is a tree of order n, then gamma_r(T) is greater than or equal to (n+2)/3. We show that gamma_tr(T) is greater than or equal to (n+2)/2. Moreover, we show that if n is congruent to 0 mod 4, then gamma_tr(T) is greater than or equal to (n+2)/2 + 1. We then constructively characterize the extremal trees achieving these lower bounds. Finally, if G is a graph of order n greater than or equal to 2, such that both G and G\u27 are not isomorphic to P_3, then gamma_r(G) + gamma_r(G\u27) is greater than or equal to 4 and less than or equal to n +2. We provide a similar result for total restrained domination and characterize the extremal graphs G of order n achieving these bounds
Restrained and Other Domination Parameters in Complementary Prisms.
In this thesis, we will study several domination parameters of a family of graphs known as complementary prisms. We will first present the basic terminology and definitions necessary to understand the topic. Then, we will examine the known results addressing the domination number and the total domination number of complementary prisms. After this, we will present our main results, namely, results on the restrained domination number of complementary prisms. Subsequently results on the distance - k domination number, 2-step domination number and stratification of complementary prisms will be presented. Then, we will characterize when a complementary prism is Eulerian or bipartite, and we will obtain bounds on the chromatic number of a complementary prism. We will finish the thesis with a section on possible future problems
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