Erdős–Rado sunflower conjecture

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Let [n]:={1,2,…,n}[n]:=\{1,2,\ldots,n\}. For k≥3k\geq 3, a family F\mathcal{F} of subsets of [n][n] is kk-sunflower free if it contains no kk pairwise distinct sets whose pairwise intersections are all equal. In the uniform setting, every member of F\mathcal{F} has size mm. Erdős–Rado sunflower conjecture. For k≥3k\geq 3, let F\mathcal{F} be a kk-sunflower free family of mm-subsets of [n][n]. Then

∣F∣≤μm|\mathcal{F}|\leq \mu^m

for a constant μ\mu depending only on kk. This is the uniform sunflower conjecture for set systems; the paper presents it as the conjecture introduced by Erdős and Rado, while the supplied text gives no resolution status.

References

Primary source

Omran Ahmadi and Hassan Norouzi, “A Polynomial Improvement of Naslund–Sawin Bound for Sunflower-Free Families Using Triangular Tensors”, arXiv:2606.30593 (2026).

Additional references

13 papers in this index state this conjecture (2014–2026). The statement above is taken from the most recent of them; the others are arXiv:2606.02667, arXiv:2605.12232, arXiv:2605.21208, arXiv:2310.15527, arXiv:2307.01374, arXiv:1908.08483, arXiv:1903.00580, arXiv:1804.10050, arXiv:1702.02831, arXiv:1606.09575, arXiv:1601.04897, arXiv:1411.4692.

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