35 papers · 1 filter
Non-dissective coverings by planks
Andrey Kupavskii, Janos Pach
A plank is the part of space between two parallel planes. The following open problem, posed 45 years ago, can be viwed as the converse of Tarski's plank problem (Bang's theorem): I…
A complete -intersection theorem for families of spanning trees
Elizaveta Iarovikova, Andrey Kupavskii
Let denote the set of all labelled spanning trees of . A family is -intersecting if for all the trees…
The Erdős-Rado Sunflower Problem for Vector Spaces
Ferdinand Ihringer, Andrey Kupavskii
The famous Erdős-Rado sunflower conjecture suggests that an -sun\-flower-free family of -element sets has size at most for some absolute constant . In this note,…
The Hajnal--Rothschild problem
Peter Frankl, Andrey Kupavskii
For a family define as the largest for which there exist such that for we have . Wha…
Intersecting Families of Spanning Trees
Peter Frankl, Glenn Hurlbert, Ferdinand Ihringer +4
A family of spanning trees of the complete graph on vertices is \emph{-intersecting} if any two members have a forest on edges in common. We prove an…
Linear dependencies, polynomial factors in the Duke--Erd\H os forbidden sunflower problem
Andrey Kupavskii, Fedor Noskov
We call a family of sets a \textit{sunflower with petals} if, for any distinct , one has . The set $…