منابع مشابه
Homomorphism-homogeneous graphs
We answer two open questions posed by Cameron and Nesetril concerning homomorphismhomogeneous graphs. In particular we show, by giving a characterization of these graphs, that extendability to monomorphism or to homomorphism leads to the same class of graphs when defining homomorphism-homogeneity. Further we show that there are homomorphism-homogeneous graphs that do not contain the Rado graph ...
متن کاملCountable connected-homogeneous graphs
A graph is connected-homogeneous if any isomorphism between finite connected induced subgraphs extends to an automorphism of the graph. In this paper we classify the countably infinite connectedhomogeneous graphs. We prove that if Γ is connected countably infinite and connected-homogeneous then Γ is isomorphic to one of: Lachlan and Woodrow’s ultrahomogeneous graphs; the generic bipartite graph...
متن کاملSet-homogeneous directed graphs
A directed graph is set-homogeneous if, whenever U and V are isomorphic finite subdigraphs, there is an automorphism g of the digraph with Ug = V . Here, extending work of Lachlan on finite homogeneous digraphs, we classify finite set-homogeneous digraphs, where we allow some pairs of vertices to have arcs in both directions. Under the assumption that such pairs of vertices are not allowed, we ...
متن کاملCountable homogeneous multipartite graphs
We give a classification of all the countable homogeneous multipartite graphs. This generalizes the similar result for bipartite graphs given in [5]. 2010 Mathematics Subject Classification 05C99 keywords: multipartite graph, homogeneous, classification
متن کاملMetrically Homogeneous Graphs
We give a catalog of the known metrically homogeneous graphs, and with proofs of existence, mainly via Fraıssé theory. We also give some classification results.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Combinatorial Theory, Series B
سال: 1981
ISSN: 0095-8956
DOI: 10.1016/0095-8956(81)90065-4