Title
On the complexity of the 3-kernel problem in some classes of digraphs.
Abstract
Let D be a digraph with the vertex set V(D) and the arc set A(D). A subset N of V(D) is k-independent if for every pair of vertices u, v is an element of N, we have d(u, v), d(v,, u) >= k; it is 1- absorbent if for every u is an element of V(D) - N there exists v is an element of N such that d(u, v) <= l. A k-kernel of D is a k-independent and (k - 1)-absorbent subset of V(D). A 2-kernel is called a kernel. It is known that the problem of determining whether a digraph has a kernel ("the kernel problem") is NP-complete, even in quite restricted families of digraphs. In this paper we analyze the computational complexity of the corresponding 3-kernel problem, restricted to three natural families of digraphs. As a consequence of one of our main results we prove that the kernel problem remains NP-complete when restricted to 3-colorable digraphs.
Year
DOI
Venue
2014
10.7151/dmgt.1727
DISCUSSIONES MATHEMATICAE GRAPH THEORY
Keywords
Field
DocType
kernel,3-kernel,NP-completeness,multipartite tournament,cyclically 3-partite digraphs,k-quasi-transitive digraph
Kernel (linear algebra),Discrete mathematics,Combinatorics,Vertex (geometry),Mathematics,Digraph,Computational complexity theory
Journal
Volume
Issue
ISSN
34
1
1234-3099
Citations 
PageRank 
References 
3
0.45
6
Authors
2
Name
Order
Citations
PageRank
Pavol Hell12638288.75
César Hernández-Cruz23310.41