## Abstract We prove that the minimum number of edges in a vertexβdiameterβ2βcritical graph on __n__ββ₯β23 vertices is (5__n__βββ17)/2 if __n__ is odd, and is (5__n__/2)βββ7 if __n__ is even. Β© 2005 Wiley Periodicals, Inc. J Graph Theory
Maximal and Minimal Vertex-Critical Graphs of Diameter Two
β Scribed by Jing Huang; Anders Yeo
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 446 KB
- Volume
- 74
- Category
- Article
- ISSN
- 0095-8956
No coin nor oath required. For personal study only.
β¦ Synopsis
A graph is vertex-critical if deleting any vertex increases its diameter. We construct, for each & 5 except &=6, a vertex-critical graph of diameter two on & vertices with at least
, where c 2 is some constant. We also construct, for each & 5 except &=6, a vertex-critical graph of diameter two on & vertices with at most 1 2 (5&&12) edges. We show that such a graph must contain at least 1 2 (5&&29) edges.
for every v # V(G ).
π SIMILAR VOLUMES
## 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
## Abstract A graph __H__ is __collapsible__ if for every subset X β __V(H), H__ has a spanning connected subgraph whose set of oddβdegree vertices is X. In any graph __G__ there is a unique collection of maximal collapsible subgraphs, and when all of them are contracted, the resulting contraction
## Abstract For any __d__β©Ύ5 and __k__β©Ύ3 we construct a family of Cayley graphs of degree __d__, diameter __k__, and order at least __k__((__d__β3)/3)^__k__^. By comparison with other available results in this area we show that our family gives the largest currently known Cayley graphs for a wide ra
Suppose G is a graph of n vertices and diameter at most d having the property that, after deleting any vertex, the resulting subgraph has diameter at most 6. Then G contains at least max{n. r(4n -8)/31} edges if 4 s d s 6 . ## 1. Introduction We consider finite undirected simple graphs. (Terminolo