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)
Medians of arbitrary graphs
β Scribed by Peter J. Slater
- Publisher
- John Wiley and Sons
- Year
- 1980
- Tongue
- English
- Weight
- 165 KB
- Volume
- 4
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
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 for which the subgraph of H induced by the median vertices is isomorphic to G.
π SIMILAR VOLUMES
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 commuti
## 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.
## Abstract The cube polynomial __c__(__G__,__x__) of a graph __G__ is defined as $\sum\nolimits\_{i \ge 0} {\alpha \_i ( G)x^i }$, where Ξ±~i~(__G__) denotes the number of induced __i__βcubes of __G__, in particular, Ξ±~0~(__G__) = |__V__(__G__)| and Ξ±~1~(__G__) = |__E__(__G__)|. Let __G__ be a medi
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