Title
Clique-width minimization is NP-hard
Abstract
Clique-width is a graph parameter that measures in a certain sense the complexity of a graph. Hard graph problems (e.g., problems expressible in Monadic Second Order Logic with second-order quantification on vertex sets, that includes NP-hard problems) can be solved efficiently for graphs of small clique-width. It is widely believed that determining the clique-width of a graph is NP-hard; in spite of considerable efforts, no NP-hardness proof has been found so far. We give the first hardness proof. We show that the clique-width of a given graph cannot be absolutely approximated in polynomial time unless P=NP. We also show that, given a graph G and an integer k, deciding whether the clique-width of G is at most k is NPhy complete. This solves a problem that has been open since the introduction of clique-width in the early 1990s.
Year
DOI
Venue
2006
10.1145/1132516.1132568
STOC
Keywords
Field
DocType
graph parameter,monadic second order logic,np-hardness proof,clique-width minimization,graph g,hard graph problem,np-hard problem,problems expressible,integer k,hardness proof,small clique-width,polynomial time,clique width,np completeness,np hard problem,second order,pathwidth
Discrete mathematics,Circulant graph,Combinatorics,Line graph,Clique graph,Cubic graph,Null graph,Clique-width,Mathematics,Voltage graph,Complement graph
Conference
ISBN
Citations 
PageRank 
1-59593-134-1
32
1.20
References 
Authors
28
4
Name
Order
Citations
PageRank
Michael R. Fellows14138319.37
Frances A. Rosamond230415.94
Udi Rotics371533.68
Stefan Szeider4134199.97