6,100 research outputs found
Bondage number of grid graphs
The bondage number of a nonempty graph is the cardinality of a
smallest set of edges whose removal from results in a graph with domination
number greater than the domination number of . Here we study the bondage
number of some grid-like graphs. In this sense, we obtain some bounds or exact
values of the bondage number of some strong product and direct product of two
paths.Comment: 13 pages. Discrete Applied Mathematics, 201
The bondage number of graphs on topological surfaces and Teschner's conjecture
The bondage number of a graph is the smallest number of its edges whose
removal results in a graph having a larger domination number. We provide
constant upper bounds for the bondage number of graphs on topological surfaces,
improve upper bounds for the bondage number in terms of the maximum vertex
degree and the orientable and non-orientable genera of the graph, and show
tight lower bounds for the number of vertices of graphs 2-cell embeddable on
topological surfaces of a given genus. Also, we provide stronger upper bounds
for graphs with no triangles and graphs with the number of vertices larger than
a certain threshold in terms of the graph genera. This settles Teschner's
Conjecture in positive for almost all graphs.Comment: 21 pages; Original version from January 201
The Algorithmic Complexity of Bondage and Reinforcement Problems in bipartite graphs
Let be a graph. A subset is a dominating set if
every vertex not in is adjacent to a vertex in . The domination number
of , denoted by , is the smallest cardinality of a dominating set
of . The bondage number of a nonempty graph is the smallest number of
edges whose removal from results in a graph with domination number larger
than . The reinforcement number of is the smallest number of
edges whose addition to results in a graph with smaller domination number
than . In 2012, Hu and Xu proved that the decision problems for the
bondage, the total bondage, the reinforcement and the total reinforcement
numbers are all NP-hard in general graphs. In this paper, we improve these
results to bipartite graphs.Comment: 13 pages, 4 figures. arXiv admin note: substantial text overlap with
arXiv:1109.1657; and text overlap with arXiv:1204.4010 by other author
The bondage number of random graphs
A dominating set of a graph is a subset of its vertices such that every
vertex not in is adjacent to at least one member of . The domination
number of a graph is the number of vertices in a smallest dominating set of
. The bondage number of a nonempty graph is the size of a smallest set
of edges whose removal from results in a graph with domination number
greater than the domination number of . In this note, we study the bondage
number of binomial random graph . We obtain a lower bound that matches
the order of the trivial upper bound. As a side product, we give a one-point
concentration result for the domination number of under certain
restrictions
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