Title
Erdős–ko–rado in random hypergraphs
Abstract
Let 3 ≤ k n/2. We prove the analogue of the Erdős–Ko–Rado theorem for the random k-uniform hypergraph Gk(n, p) when k n/2)1/3; that is, we show that with probability tending to 1 as n → ∞, the maximum size of an intersecting subfamily of Gk(n, p) is the size of a maximum trivial family. The analogue of the Erdős–Ko–Rado theorem does not hold for all p when k ≫ n1/3. We give quite precise results for k n1/2−ϵ. For larger k we show that the random Erdős–Ko–Rado theorem holds as long as p is not too small, and fails to hold for a wide range of smaller values of p. Along the way, we prove that every non-trivial intersecting k-uniform hypergraph can be covered by k2 − k + 1 pairs, which is sharp as evidenced by projective planes. This improves upon a result of Sanders [7]. Several open questions remain.
Year
DOI
Venue
2009
10.1017/S0963548309990253
Combinatorics, Probability & Computing
Keywords
Field
DocType
intersecting subfamily,rado theorem,random k-uniform hypergraph,k n,random erd,larger k,k n1,maximum size,maximum trivial family,k-uniform hypergraph,random hypergraphs,projective plane
Discrete mathematics,Combinatorics,Constraint graph,Hypergraph,Projective plane,Mathematics
Journal
Volume
Issue
ISSN
18
5
0963-5483
Citations 
PageRank 
References 
5
0.67
4
Authors
3
Name
Order
Citations
PageRank
József Balogh186289.91
Tom Bohman225033.01
Dhruv Mubayi357973.95