Title
Almost every complement of a tadpole graph is not chromatically unique.
Abstract
The study of chromatically unique graphs has been drawing much attention and many results are surveyed in [4, 12, 13]. The notion of adjoint polynomials of graphs was first introduced and applied to the study of the chromaticity of the complements of the graphs by Liu [17] (see also [4]). Two invariants for adjoint equivalent graphs that have been employed successfully to determine chromatic unique graphs were introduced by Liu [17] and Dong et al. [4] respectively. In the paper, we shall utilize, among other things, these two invariants to investigate the chromaticity of the complement of the tadpole graphs C-n(P-m), the graph obtained from a path P-m and a cycle C-n by identifying a pendant vertex of the path with a vertex of the cycle. Let (G) over bar stand for the complement of a graph G. We prove the following results: 1. The graph <(Cn-1(P-2))over bar> is chromatically unique if and only if n not equal 5, 7. 2. Almost every <(C-n(P-m))over bar> is not chromatically unique, where n >= 4 and m >= 2.
Year
DOI
Venue
2013
null
ARS COMBINATORIA
Keywords
Field
DocType
chromatic polynomials,chromatically unique,adjoint polynomials,adjointly unique,characters
Discrete mathematics,Indifference graph,Combinatorics,Vertex (geometry),Chromatic scale,Polynomial,Chordal graph,Invariant (mathematics),Pathwidth,Mathematics,Complement graph
Journal
Volume
Issue
ISSN
108
null
0381-7032
Citations 
PageRank 
References 
0
0.34
6
Authors
6
Name
Order
Citations
PageRank
J. F. Wang100.34
Xiaoqi Huang2103.52
K. L. Teo31643211.47
Francesco Belardo4158.54
R. Y. Liu500.34
C. F. Ye600.34