Glock–Kühn–Lo–Osthus, Kelly, and Kwan–Sah–Sawhney–Simkin conjectures

Let AnA_n be the number of Steiner triple systems of order nn containing no Pasch configuration, and let BnB_n be the number of Latin squares of order nn containing no 2×22\times 2 Latin subsquare (intercalate). Determine the asymptotic growth of AnA_n and BnB_n as n→∞n\to\infty—along admissible orders for Steiner triple systems—including their values up to multiplicative factors of the form exp⁡(o(n2))\exp(o(n^2)), equivalently determine log⁡An\log A_n and log⁡Bn\log B_n up to additive o(n2)o(n^2) terms.

References

Primary source

arXiv

Additional references

Progress summary

Refreshed
Claimed progress

A new unrefereed paper supplies sharper estimates for several parts of these conjectures, but does not settle the full bundle.

The entry concerns conjectures on sparse-configuration avoidance and enumeration, including Pasch-free Steiner triple systems and Latin squares without 2×22\times 2 subsquares. The reported advance addresses critical transition regimes rather than proving all conjectures uniformly.

Known results

  • Kwan, Sah, Sawhney, and Simkin (2022) established existence of Latin squares with arbitrarily high girth and derived lower bounds for intercalate-free Latin squares.
  • Delcourt, Henderson, Lesgourgues, and Postle (2025) proved the Glock--Kühn--Osthus conjecture in a minimum-degree range δ(G)≥0.82733n\delta(G)\ge 0.82733n.
  • Jain and Pham (2022) obtained threshold results for Latin squares and Steiner triple systems in random 33-uniform hypergraphs.

October 2026 critical-regime estimates

Kwan and Pham derive a variational formula for triangle-free probabilities at p=c/np=c/\sqrt{n}, identify a phase transition near c≈4.341c\approx 4.341, and estimate counts of Pasch-free Steiner triple systems and Latin squares without 2×22\times 2 subsquares, up to factors of exp⁡(o(n2))\exp(o(n^2)). The manuscript explicitly provides estimates rather than a uniform resolution and is unrefereed.

Current status (as of October 2026): Several ranges and enumeration estimates are established, while the combined conjecture entry remains unresolved; the newest critical-regime claims are unverified.

Sources

Solutions 0

No solutions have been posted yet.