Title
Containment of butterflies in networks constructed by the line digraph operation
Abstract
Let G be a digraph. Let L(G) and U(G) denote the line digraph of G and the underlying graph of G, respectively. A network constructed by the line digraph operation means a graph defined by U(L(k)(G)) for some digraph G and some integer k, where L(k)(G) = L(L(k-1)(G)). Let delta(G) be the minimum degree of the vertices of G. Let b(k,r) denote the r-dimensional k-ary butterfly graph. It is proved that b(1,r), b(2,r), ..., b(delta(G)-1,r) are contained in U(L(r)(G)) such that they are vertex-disjoint. Also it is proved that k(Sigma(1 less than or equal to i<[delta(G)/k]i(r) + [delta(G)/k](r){delta(G)/k}) vertex-disjoint copies of b(k,r) are contained in U(L(r)(G)), where for a real x, [x] and {x} stand for the greatest integer not exceeding x and the fractional part of x, respectively. As corollaries of these results, we can get results on the containment of butterflies in the de Bruijn and Kautz graphs.
Year
DOI
Venue
1997
10.1016/S0020-0190(96)00183-4
Inf. Process. Lett.
Keywords
Field
DocType
line digraph operation,de bruijn graph,containment,parallel processing
Integer,Discrete mathematics,Graph,Combinatorics,Vertex (geometry),Parallel processing,De Bruijn sequence,Butterfly graph,Fractional part,Mathematics,Digraph
Journal
Volume
Issue
ISSN
61
1
0020-0190
Citations 
PageRank 
References 
2
0.43
8
Authors
2
Name
Order
Citations
PageRank
Toru Hasunuma114216.00
Yukio Shibata220.43