Balko–Vizer ordered Ramsey problem

Determine whether there exists an absolute constant c>0c>0 such that, for every integer d≥1d\ge 1, there is a constant Cd>0C_d>0 for which every weakly dd-degenerate ordered 33-uniform hypergraph HH on tt vertices satisfies r<(H,K3(3)(n))≤t 2Cdn2−c/dr_<\bigl(H,K_3^{(3)}(n)\bigr)\le t\,2^{C_d n^{2-c/d}} for every positive integer nn.

References

Primary source

arXiv

Additional references

Progress summary

Refreshed
Claimed solved

A September 2026 preprint claims to close the main gap in the ordered Ramsey problem, but the result has not been independently verified.

The problem asks for sharp ordered Ramsey bounds for ordered 33-uniform hypergraphs with bounded degree, strengthening the earlier Balko–Vizer estimates. The central question was whether the gap between the known upper and lower bounds could be closed.

Known results

  • Balko and Vizer, 2021: for bounded maximum degree and interval chromatic number 33, they proved a subquadratic exponential upper bound, while a substantial gap with lower bounds remained.

September 2026 claimed resolution

Wen Chen, Zihan He, Qizhong Lin, and Meng Liu claim an exponential bound with exponent n2−c/dn^{2-c/d} in the weakly degenerate ordered 33-uniform setting, and show that bounded weak degeneracy cannot generally be replaced by bounded standard degeneracy. This appears to answer the cited problem, but the claim is unverified.

Current status (as of September 2026): The original gap is claimed to be closed for the stated weakly degenerate ordered 33-uniform setting; independent verification is pending, and the result does not settle the broader ordered-hypergraph question.

Sources

Solutions 0

No solutions have been posted yet.