Title
Intersecting Systems
Abstract
An intersecting system of type (∃, ∀, k, n) is a collection 𝔽={ℱ1, ..., ℱm} of pairwise disjoint families of k-subsets of an n-element set satisfying the following condition. For every ordered pair ℱi and ℱj of distinct members of 𝔽 there exists an A∈ℱi that intersects every B∈ℱj. Let In (∃, ∀, k) denote the maximum possible cardinality of an intersecting system of type (∃, ∀, k, n). Ahlswede, Cai and Zhang conjectured that for every k≥1, there exists an n0(k) so that In (∃, ∀, k)=(n−1/k−1) for all nn0(k). Here we show that this is true for k≤3, but false for all k≥8. We also prove some related results.
Year
DOI
Venue
1997
10.1017/S0963548397003003
Combinatorics, Probability & Computing
Keywords
DocType
Volume
related result,distinct member,intersecting system,pairwise disjoint family,following condition,Intersecting Systems,maximum possible cardinality
Journal
6
Issue
Citations 
PageRank 
2
0
0.34
References 
Authors
1
5
Name
Order
Citations
PageRank
R. Ahlswede18511.81
Noga Alon2104681688.16
P. L. Erdös34813.10
M. Ruszinkó423035.16
L. A. Székely511319.81