Frankl–Kupavskii conjecture for the Erdős–Kleitman problem

From papers

For integers ns2n\ge s\ge2, define

e(n,s)=max{F:F2[n] and ν(F)<s}.e(n,s)=\max\{ |\mathcal F|:\mathcal F\subseteq2^{[n]}\text{ and }\nu(\mathcal F)<s\}.

For integers m1m\ge1 and 1s/21\le\ell\le\lceil s/2\rceil, set n=(m+1)sn=(m+1)s-\ell and, for any L([n]1)L\in\binom{[n]}{\ell-1}, define

P(m,s,;L)={A[n]:A+ALm+1},P(m,s,\ell;L)=\{A\subseteq[n]: |A|+|A\cap L|\ge m+1\},

and write P(m,s,)|P(m,s,\ell)| for its size. Frankl–Kupavskii conjecture. Under these assumptions,

e(n,s)=P(m,s,).e(n,s)=|P(m,s,\ell)|.

The family P(m,s,;L)P(m,s,\ell;L) supplies a natural lower bound because it has no ss pairwise disjoint members. The conjecture remains open in the stated range, with m=3m=3 identified as the first unresolved value in the conjectured range.

Progress summary

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Sources & referencesView supporting material

Primary source

Cheng Chi and Yan Wang, “A solution to Frankl and Kupavskii's conjecture concerning Erdős-Kleitman matching problem”, arXiv:2605.06389 (2026).

Solutions 0

No solutions have been posted yet.