## Abstract Let __G__ be connected simple graph with diameter __d__(__G__). __G__ is said __v__^+^βcritical if __d__(__G__β__v__) is greater than __d__(__G__) for every vertex __v__ of __G__. Let Dβ² = max {__d__(__G__β__v__) : __v__ β __V__(__G__)}. Boals et al. [Congressus Numerantium 72 (1990), 1
On graphs with prescribed median I
β Scribed by G. R. T. Hendry
- Publisher
- John Wiley and Sons
- Year
- 1985
- Tongue
- English
- Weight
- 202 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
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. It is shown that if G has n vertices and minimum degree 6 then f(G) s 2n -6 + 1. Graphs having both median and center prescribed are constructed. It is also shown that if the vertices of a K, are removed from a graph H, then at most r components of the resulting graph contain median vertices of H.
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 We determine the minimum number of edges in a regular connected graph on __n__ vertices, containing a complete subgraph of order __k__ β€ __n__/2. This enables us to confirm and strengthen a conjecture of P. ErdΓΆs on the existence of regular graphs with prescribed chromatic number.
## Abstract Chartrand and Stewart have shown that the line graph of an __n__βconnected graph is itself __n__βconnected. This paper shows that for every pair of integers __m__ > __n__ > 1 there is a graph of point connectivity __n__ whose line graph has point connectivity __m__. The corresponding qu