Erdős–Rado sunflower conjecture
Openerdos-sunflower
Statement
A -sunflower is a family of sets with a common pairwise intersection (core). Prove that any family of more than sets of size contains a -sunflower, for a constant depending only on .
Current frontier
erdosproblems.com/20, OPEN. Erdős–Rado (1960) gave ; Alweiss–Lovett–Wu–Zhang (2020) and refinements reached . The conjectured (no in the base) is open, including .
When this counts as solved
QUANTITATIVE. PROOF_COMPLETE for the bound, COUNTEREXAMPLE for faster growth. BREAKTHROUGH for removing the residual factor for general , or settling .
Classification
quantitative