The distance of a vertex u in a connected graph H is the sum of all the distances from u to the other vertices of H. The median M(H) of H is the subgraph of H induced by the vertices of minimum distance. For any graph G, let f ( G ) denote the minimum order of a connected graph H satisfying M(H) = G
On compact median graphs
β Scribed by Tardif, Claude
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 715 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
A median graph is called compact if it does not contain an isometric ray. This property is shown to be equivalent to the finite intersection property for convex sets. We show that a compact median graph contains a finite cube that is fixed by all of its automorphisms, and that each family of commuting endomorphisms of a compact median graph fixes a common cube.
π SIMILAR VOLUMES
## Abstract For each vertex __u__ in a connected graph __H__, the __distance__ of __u__ is the sum of the distances from __u__ to each of the vertices __v__ of __H.__ A vertex of minimum distance in __H__ is called a __median__ vertex. It is shown that for any graph __G__ there exists a graph __H__
Let G be connected graph and S a set of vertices of G. Then a Steiner tree for S is a connected subgraph of G of smallest size (number of edges) that contains S. The size of such a subgraph is called the Steiner distance for S and is denoted by d(S). For a vertex v of G, and integer n, 2 Υ n Υ ΝV(G)
## Abstract The nβcube is characterized as a connected regular graph in which for any three vertices __u, v__, and __w__ there is a unique vertex that lies simultaneously on a shortest (__u, v__)βpath, a shortest (__v, w__)βpath, and a shortest (__w, u__)βpath.
Hypercubes are characterized among connected bipartite graphs by interval conditions in several ways. These results are based on the following two facts: (i) connected bipartite graphs are median provided that all their intervals induce median graphs, and (ii) median (0, 2)graphs are hypercubes. No