Improved upper bounds for the Poljak–Rödl function

Improve the upper bound f(m) ≤ ⌈m/2⌉ + 3 for the Poljak–Rödl function and determine whether lim sup f(n)/n = 0.

Background

The best stated general upper bound is f(m) ≤ ⌈m/2⌉ + 3. The authors explain that improving this bound may require proving stronger chromatic lower bounds for exponential graphs of the form K_n{Ωw(K{m'})}. They also ask whether the ratio f(n)/n tends to zero along the upper limit.

References

Can the upper bound $f(m) \le \lceil m/2 \rceil +3$ be improved? Is it true that $\lim \sup f(n)/n = 0$?

— A survey on Hedetniemi's conjecture  (2502.16078 - Zhu, 22 Feb 2025) in Section 5, Question q2

The argument does not handle the finitely many smaller values of $m$. Finding those values and describing the colorings near the threshold remain natural open problems.

— The Ramsey threshold for trees versus odd cycles  (2609.00944 - Lin et al., 1 Sep 2026) in Concluding remarks, final section