139 research outputs found
A note on tilted Sperner families with patterns
Let and be two nonnegative integers with and . We call
a \textit{(p,q)-tilted Sperner family
with patterns on [n]} if there are no distinct with:
Long (\cite{L}) proved that the cardinality of a (1,2)-tilted Sperner family
with patterns on is
We improve and generalize this result, and prove that the cardinality of
every ()-tilted Sperner family with patterns on [] is Comment: 8 page
On Tur\'an problems with bounded matching number
Very recently, Alon and Frankl initiated the study of the maximum number of
edges in -vertex -free graphs with matching number at most . For fixed
and , we determine this number apart from a constant additive term. We
also obtain several exact results
Rainbow copies of in families of
We study the following problem. How many distinct copies of can an
-vertex graph have, if does not contain a rainbow , that is, a
copy of where each edge is contained in a different copy of ? The case
is equivalent to the Tur\'an problem for Berge hypergraphs, which has
attracted several researchers recently. We also explore the connection of our
problem to the so-called generalized Tur\'an problems. We obtain several exact
results. In the particularly interesting symmetric case where , we
completely solve the case is the 3-edge path, and asymptitically solve the
case is a book graph
- …