2 research outputs found
On a covering problem in the hypercube
In this paper, we address a particular variation of the Tur\'an problem for
the hypercube. Alon, Krech and Szab\'o (2007) asked "In an n-dimensional
hypercube, Qn, and for l < d < n, what is the size of a smallest set, S, of
Q_l's so that every Q_d contains at least one member of S?" Likewise, they
asked a similar Ramsey type question: "What is the largest number of colors
that we can use to color the copies of Q_l in Q_n such that each Q_d contains a
Q_l of each color?" We give upper and lower bounds for each of these questions
and provide constructions of the set S above for some specific cases.Comment: 8 page
On the decomposition of random hypergraphs
For an -uniform hypergraph , let be the minimum number of
complete -partite -uniform subhypergraphs of whose edge sets
partition the edge set of . For a graph , is the bipartition
number of which was introduced by Graham and Pollak in 1971. In 1988,
Erd\H{o}s conjectured that if , then with high probability
, where is the independence number of . This
conjecture and related problems have received a lot of attention recently. In
this paper, we study the value of for a typical -uniform hypergraph
. More precisely, we prove that if and
, then with high probability
, where is the
Tur\'an density of .Comment: corrected few typos. updated the referenc