Hamiltonicity and restricted block-intersection graphs of -designs
β Scribed by David A. Pike; Robert C. Vandell; Matthew Walsh
- Book ID
- 108114159
- Publisher
- Elsevier Science
- Year
- 2009
- Tongue
- English
- Weight
- 344 KB
- Volume
- 309
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
π SIMILAR VOLUMES
Given a BIBD S = (V, B), its 1-block-intersection graph GS has as vertices the elements of B; two vertices B1, B2 β B are adjacent in GS if |B1 β© B2| = 1. If S is a triple system of arbitrary index Ξ», it is shown that GS is hamiltonian.
A graph G is n-existentially closed (n-e.c.) if for each pair (A,B) of disjoint subsets of V(G) with |A|+|B|β€n there exists a vertex in V(G)\(AβͺB) which is adjacent to each vertex in A and to no vertex in B. In this paper we study the n-existential closure property of block intersection graphs of in
In this article we study the n-existential closure property of the block intersection graphs of infinite t-(v, k, k) designs for which the block size k and the index k are both finite. We show that such block intersection graphs are 2-e.c. when 2 β€ t β€ k-1. When k = 1 and 2 β€ t β€ k, then a necessary