Title
On interval representations of graphs
Abstract
The interval number i ( G ) of a graph G is the least integer i such that G is the intersection graph of sets of at most i intervals of the real line. The local track number l ( G ) is the least integer l such that G is the intersection graph of sets of at most l intervals of the real line and such that two intervals of the same vertex belong to different components of the interval representation. The track number t ( G ) is the least integer t such that E ( G ) is the union of t interval graphs. We show that the local track number of a planar graph with girth at least 7 is at most 2. We also answer a question of West and Shmoys in 1984 by showing that the recognition of 2-degenerate planar graphs with maximum degree 5 and interval number at most 2 is NP-complete.
Year
DOI
Venue
2016
10.1016/j.dam.2015.08.022
Discrete Applied Mathematics
Keywords
Field
DocType
planar graphs,np completeness
Discrete mathematics,Combinatorics,Indifference graph,Graph toughness,Line graph,Interval graph,Graph power,Pathwidth,1-planar graph,Intersection number (graph theory),Mathematics
Journal
Volume
Issue
ISSN
202
C
0166-218X
Citations 
PageRank 
References 
1
0.37
9
Authors
3
Name
Order
Citations
PageRank
aquiles braga de queiroz110.37
Valentin Garnero2123.31
Pascal Ochem325836.91