## 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__
A new characterization of median graphs
β Scribed by Abdelhafid Berrachedi
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 171 KB
- Volume
- 128
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
β¦ Synopsis
A graph is Hilbertian if for any three vertices u, v and w, the interval I(u, u) contains a unique nearest vertex p from w. We show that a graph is median if and only if it is Hilbertian.
π SIMILAR VOLUMES
A median graph is a ewtmected ,~raph, such that for am.' three ,~ertices u, v aad w there is exactly one ~x:rtex x that lies simutt~ neously on a shortest (lz,,) .pa'~5. a shortest (v. w)-path and a shortest (u'.t,~-pa~h. !t is proved that a median graph cm, "t..-obtained from a one-vertex graph by
One of the first characterizations of interval graphs, given by Lekkerkerker and Boland (1962), uses the concept of an asteroidal triple. In this paper we give a similar characterization on the proper interval graphs using the akin concept of an astral triple.
The following result is proven: every edge-preserving self-map of a median graph leaves a cube invariant. This extends a fixed edge theorem for trees and parallels a result on invariant simplices in contractible graphs.