Title
Smaller superconcentrators of density 28
Abstract
An N-superconcentrator is a directed, acyclic graph with N input nodes and N output nodes such that every subset of the inputs and every subset of the outputs of same cardinality can be connected by node-disjoint paths. It is known that linear-size and bounded-degree superconcentrators exist. Here it is proved that such superconcentrators exist (by a random construction of certain expander graphs as building blocks) having density 28 (where the density is the number of edges divided by N). The best known density before this paper was 34.2 [U. Schöning, Construction of expanders and superconcentrators using Kolmogorov complexity, J. Random Structures Algorithms 17 (2000) 64-77] or 33 [L.A. Bassalygo, Personal communication, 2004].
Year
DOI
Venue
2006
10.1016/j.ipl.2006.01.006
Inf. Process. Lett.
Keywords
Field
DocType
l.a. bassalygo,u. schoning,bounded-degree superconcentrators,smaller superconcentrators,kolmogorov complexity,combinatorial problem,random construction,superconcentrator,n output,n input node,acyclic graph,u. sch,j. random structures algorithms,known density,computational complexity,directed acyclic graph,expander graph
Discrete mathematics,Combinatorics,Random graph,Expander graph,Division (mathematics),Kolmogorov complexity,Cardinality,Directed graph,Directed acyclic graph,Mathematics,Computational complexity theory
Journal
Volume
Issue
ISSN
98
4
0020-0190
Citations 
PageRank 
References 
1
0.36
7
Authors
1
Name
Order
Citations
PageRank
Uwe Schöning1998105.69