Title
Recognizing vertex intersection graphs of paths on bounded degree trees
Abstract
An ( h , s , t ) -representation of a graph G consists of a collection of subtrees of a tree T , where each subtree corresponds to a vertex of G such that (i) the maximum degree of T is at most h , (ii) every subtree has maximum degree at most s , (iii) there is an edge between two vertices in the graph G if and only if the corresponding subtrees have at least t vertices in common in T . The class of graphs that has an ( h , s , t ) -representation is denoted by h , s , t ] .An undirected graph G is called a V P T graph if it is the vertex intersection graph of a family of paths in a tree. Thus, h , 2 , 1 ] graphs are the V P T graphs that can be represented in a tree with maximum degree at most h . In this paper we characterize h , 2 , 1 ] graphs using chromatic number. We show that the problem of deciding whether a given V P T graph belongs to h , 2 , 1 ] is NP-complete, while the problem of deciding whether the graph belongs to h , 2 , 1 ] - h - 1 , 2 , 1 ] is NP-hard. Both problems remain hard even when restricted to V P T ¿ S p l i t . Additionally, we present a non-trivial subclass of V P T ¿ S p l i t in which these problems are polynomial time solvable.
Year
DOI
Venue
2014
10.1016/j.dam.2013.08.004
Discrete Applied Mathematics
Keywords
Field
DocType
non-trivial subclass,graph g,vpt graph,chromatic number,subtree corresponds,maximum degree,corresponding subtrees,bounded degree tree,undirected graph,polynomial time solvable,vertex intersection graph
Discrete mathematics,Block graph,Graph toughness,Combinatorics,Graph power,Neighbourhood (graph theory),Degree (graph theory),Symmetric graph,1-planar graph,Mathematics,Pancyclic graph
Journal
Volume
Issue
ISSN
162
C
0166-218X
Citations 
PageRank 
References 
3
0.47
15
Authors
3
Name
Order
Citations
PageRank
Liliana Alcón15914.43
Marisa Gutierrez2186.59
M. P. Mazzoleni3124.05