Title
Blocking Quadruple: A New Obstruction to Circular-Arc Graphs.
Abstract
Finding a forbidden subgraph characterization of circular-arc graphs is a challenging open problem. Many partial results toward this goal have been proposed over the years, but a satisfactory answer has so far eluded us. In this paper, we suggest a new direction in this line of research. We propose a novel structural obstruction to circular-arc graphs-a blocking quadruple- and study its use in characterizing circular-arc graphs within chordal graphs. Notably, we observe that the absence of blocking quadruples unifies characterizations of various known chordal subclasses of circular-arc graphs found in the literature. To this end, we provide a forbidden induced subgraph characterization of chordal graphs without blocking quadruples and show that the absence of blocking quadruples exactly characterizes chordal circular-arc graphs of independence number 4 or less. Our proof uses an interesting geometric approach, constructing a circular-arc representation by traversing around a carefully chosen clique tree. In fact, we prove that this characterizes circular-arc representability of all chordal graphs.
Year
DOI
Venue
2014
10.1137/13091717X
SIAM JOURNAL ON DISCRETE MATHEMATICS
Keywords
Field
DocType
circular-arc graph,chordal graph,asteroidal triple,forbidden subgraph characterization,Wiener index
Discrete mathematics,Combinatorics,Indifference graph,Interval graph,Lexicographic breadth-first search,Chordal graph,Treewidth,Pathwidth,Mathematics,Maximal independent set,Split graph
Journal
Volume
Issue
ISSN
28
2
0895-4801
Citations 
PageRank 
References 
1
0.36
0
Authors
3
Name
Order
Citations
PageRank
Mathew C. Francis110714.90
Pavol Hell22638288.75
Juraj Stacho39314.33