Title
Exponential Domination In Subcubic Graphs
Abstract
As a natural variant of domination in graphs, Dankelmann et al. [Domination with exponential decay, Discrete Math. 309 (2009) 5877-5883] introduced exponential domination, where vertices are considered to have some dominating power that decreases exponentially with the distance, and the dominated vertices have to accumulate a sufficient amount of this power emanating from the dominating vertices. More precisely, if S is a set of vertices of a graph G, then S is an exponential dominating set of G if Sigma(v is an element of S) (1/2)(dist(G,S)(u,v)-1) >= 1 for every vertex u in V (G) \ S, where dist((G,S))(u, v) is the distance between u is an element of V (G) \ S and v is an element of S in the graph G - (S \ {v}). The exponential domination number gamma(e)(G) of G is the minimum order of an exponential dominating set of G.In the present paper we study exponential domination in subcubic graphs. Our results are as follows. If G is a connected subcubic graph of order n(G), thenn(G)/6 log(2)(n(G) + 2) + 4 <= gamma(e)(G) <= 1/3 (n(G) + 2).For every epsilon > 0, there is some g such that gamma(e)(G) <= epsilon n(G) for every cubic graph G of girth at least g. For every 0 < alpha < 2/3ln(2), there are infinitely many cubic graphs G with gamma(e)(G) <= 3n(G)/ln(n(G))(alpha). If T is a subcubic tree, then gamma(e)(T) >= 1/6 (n(T) + 2). For a given subcubic tree, gamma(e)(T) can be determined in polynomial time. The minimum exponential dominating set problem is APX-hard for subcubic graphs.
Year
Venue
Keywords
2016
ELECTRONIC JOURNAL OF COMBINATORICS
domination, exponential domination, subcubic graph, cubic graph, girth, cage
Field
DocType
Volume
Discrete mathematics,Graph,Combinatorics,Dominating set,Exponential function,Vertex (geometry),Cubic graph,Exponential decay,Domination analysis,Mathematics
Journal
23
Issue
ISSN
Citations 
4
1077-8926
2
PageRank 
References 
Authors
0.53
13
3
Name
Order
Citations
PageRank
Stéphane Bessy111719.68
Pascal Ochem225836.91
Dieter Rautenbach3946138.87