𝔖 Bobbio Scriptorium
✦   LIBER   ✦

A new characterization of median graphs

✍ 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.

✦ 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.


πŸ“œ SIMILAR VOLUMES


Medians of arbitrary graphs
✍ Peter J. Slater πŸ“‚ Article πŸ“… 1980 πŸ› John Wiley and Sons 🌐 English βš– 165 KB

## 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__

The structure of median graphs
✍ Martyn Mulder πŸ“‚ Article πŸ“… 1978 πŸ› Elsevier Science 🌐 English βš– 473 KB

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

Median graphs and Helly hypergraphs
✍ H.M. Mulder; A. Schrijver πŸ“‚ Article πŸ“… 1979 πŸ› Elsevier Science 🌐 English βš– 963 KB
A new characterization of proper interva
✍ Zygmunt Jackowski πŸ“‚ Article πŸ“… 1992 πŸ› Elsevier Science 🌐 English βš– 379 KB

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.

A fixed cube theorem for median graphs
✍ Hans-JΓΌrgen Bandelt; Marcel van de Vel πŸ“‚ Article πŸ“… 1987 πŸ› Elsevier Science 🌐 English βš– 513 KB

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.