Berkovich–Dhar hook-length conjectures

Let On,m\mathcal{O}_{n,m} be the set of partitions λ\lambda of nn whose parts are odd and whose largest part satisfies λ1≤m\lambda_1\le m, and let Dn,m\mathcal{D}_{n,m} be the set of partitions of nn into distinct parts with λ1≤m\lambda_1\le m. If h2(λ)h_2(\lambda) denotes the number of cells of the Ferrers diagram of λ\lambda having hook length 22, then the hook-pair conjecture asserts that, for all n,m≥0n,m\ge 0, ∑λ∈On,m(h2(λ)2)≥∑λ∈Dn,m(h2(λ)2)\displaystyle \sum_{\lambda\in\mathcal{O}_{n,m}}\binom{h_2(\lambda)}{2}\ge \sum_{\lambda\in\mathcal{D}_{n,m}}\binom{h_2(\lambda)}{2}. Berkovich and Dhar also formulated a stronger coefficientwise inequality for the corresponding hook-length generating functions; the supplied source does not state that inequality explicitly.

References

Primary source

arXiv

Additional references

Progress summary

Refreshed
Claimed solved

A September 2026 preprint claims to settle both conjectures and strengthen them, but the result has not yet been independently checked.

The Berkovich–Dhar conjectures compare hook-length statistics for odd and distinct partitions. They were posed by Berkovich and Dhar; the latest claim establishes coefficientwise domination through weight-preserving injections and product identities.

Known results

  • Berkovich and Dhar proved the finite unweighted inequality, while retaining the weighted inequality as Conjecture 2.6 and the unbounded statement as Conjecture 4.1.
  • Ballantine, Burson, Craig, Folsom, and Wen (2023) proved the unweighted bias for hook lengths 22 and 33 and conjectured the analogue for every fixed hook length.
  • Craig, Dawsey, and Han proved the unbounded unweighted inequality for all sufficiently large nn, via asymptotics for every hook length h≥2h\geq 2.

September 22, 2026 claimed resolution

Rong Chen's preprint, Proofs of two conjectures of Berkovich and Dhar on hook lengths, claims proofs of both named conjectures in stronger coefficientwise form. The announcement is unconfirmed because the preprint is unrefereed.

Current status (as of September 2026): the earlier unweighted results are established, while Chen's claimed resolution of the two weighted conjectures remains unverified.

Sources

Solutions 0

No solutions have been posted yet.