Title
Characterizing the Difference Between Graph Classes Defined by Forbidden Pairs Including the Claw.
Abstract
For two graphs A and B, a graph G is called $$\{A,B\}$$-free if G contains neither A nor B as an induced subgraph. Let $$P_{n}$$ denote the path of order n. For nonnegative integers k, $$\ell $$ and m, let $$N_{k,\ell ,m}$$ be the graph obtained from $$K_{3}$$ and three vertex-disjoint paths $$P_{k+1}$$, $$P_{\ell +1}$$, $$P_{m+1}$$ by identifying each of the vertices of $$K_{3}$$ with one endvertex of one of the paths. Let $$Z_{k}=N_{k,0,0}$$ and $$B_{k,\ell }=N_{k,\ell ,0}$$. Bedrossian characterized all pairs $$\{A,B\}$$ of connected graphs such that every 2-connected $$\{A,B\}$$-free graph is Hamiltonian. All pairs appearing in the characterization involve the claw ($$K_{1,3}$$) and one of $$N_{1,1,1}$$, $$P_{6}$$ and $$B_{1,2}$$. In this paper, we characterize connected graphs that are (i) $$\{K_{1,3},Z_{2}\}$$-free but not $$B_{1,1}$$-free, (ii) $$\{K_{1,3},B_{1,1}\}$$-free but not $$P_{5}$$-free, or (iii) $$\{K_{1,3},B_{1,2}\}$$-free but not $$P_{6}$$-free. The third result is closely related to Bedrossian’s characterization. Furthermore, we apply our characterizations to some forbidden pair problems.
Year
DOI
Venue
2019
10.1007/s00373-019-02108-0
Graphs and Combinatorics
Keywords
Field
DocType
Forbidden subgraph, Hamiltonian cycle, Halin graph
Integer,Graph,Combinatorics,Vertex (geometry),Hamiltonian path,Induced subgraph,Halin graph,Mathematics
Journal
Volume
Issue
ISSN
35
6
0911-0119
Citations 
PageRank 
References 
0
0.34
0
Authors
5
Name
Order
Citations
PageRank
Guantao Chen110725.00
Michitaka Furuya23918.35
Songling Shan3209.16
Shoichi Tsuchiya494.44
Ping Yang500.68