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Cycle–graph Ramsey goodness with linear n

Determine whether there exists a constant c > 0 such that, for all graphs H and all n ≥ c · |H|, the Ramsey number r(C_n, H) equals (n − 1)(χ(H) − 1) + σ(H).

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Background

Haslegrave, Hyde, Kim, and Liu proved that r(C_n, H) achieves the lower bound (n−1)(χ(H)−1)+σ(H) when n ≥ c |H| (log χ(H))4, close to the conjectured linear threshold. Removing the polylogarithmic factor in χ(H) would settle the precise dependence on |H| alone.

References

Question [Haslegrave--Hyde--Kim--Liu ] Is there a constant c > 0 such that, if n ≥ c|H|, then r(C_n, H) = (n-1)(χ(H)-1) + σ(H)?

Sublinear expanders and their applications (2401.10865 - Letzter, 19 Jan 2024) in Ramsey goodness of cycles (Section 11)