Title
Connected-Homomorphism-Homogeneous Graphs.
Abstract
A relational structure is (connected-)homogeneous if every isomorphism between finite (connected) substructures extends to an automorphism of the structure. We investigate notions which generalise (connected-)homogeneity, where "isomorphism" may be replaced by "homomorphism" or "monomorphism" in the definition. Specifically, we study the classes of finite connected-homomorphism-homogeneous graphs, with the aim of producing classifications. The main result is a classification of the finite C-HH graphs, where a graph G is C-HH if every homomorphism from a finite connected induced subgraph of G into G extends to an endomorphism of G. The finite C-II (connected-homogeneous) graphs were classified by Gardiner in 1976, and from this we obtain classifications of the finite C-HI and C-MI finite graphs. Although not all the classes of finite connected-homomorphism-homogeneous graphs are completely characterised, we may still obtain the final hierarchy picture for these classes.
Year
DOI
Venue
2015
10.1002/jgt.21788
Journal of Graph Theory
Keywords
Field
DocType
homomorphisms
Topology,Discrete mathematics,Combinatorics,Indifference graph,Modular decomposition,Graph isomorphism,Chordal graph,Induced subgraph,Isomorphism,Homomorphism,Mathematics,Endomorphism
Journal
Volume
Issue
Citations 
78
1
1
PageRank 
References 
Authors
0.40
7
1
Name
Order
Citations
PageRank
Deborah C. Lockett110.40