combinatorics / Ramsey theory, arithmetic progressions

Erdos Problem #138: do the van der Waerden numbers grow superexponentially, W(k)^(1/k) -> infinity?

Theorem 1.1: there is an absolute K0K_0 with Wr(k)>kck⌊log⁡2r⌋W_r(k)>k^{ck\lfloor\log_2 r\rfloor}, c=10−5c=10^{-5}, for all k≥K0k\ge K_0 and r≥2r\ge2; hence Wr(k)1/k→∞W_r(k)^{1/k}\to\infty for each fixed rr. Prior work in 2026: Fox-Hunter proved superexponential growth for three colours, and Campos-Fox-Schildkraut proved W2(k)≥(1−o(1))k2k−1W_2(k)\ge(1-o(1))k2^{k-1}, settling W2(k)/2k→∞W_2(k)/2^k\to\infty but not the limit asked here. Not shown: the companion question W(k+1)−W(k)→∞W(k+1)-W(k)\to\infty, or any upper bound improvement.

22Significance / 100
1Frontier events
0Verification tasks
0Recorded attempts

Temporal state

Current frontier

No reconciled state yet.

Append-only history

Frontier timeline

combinatoricsSep 23, 2026Significance 22/100Registry: lean checked

Erdos Problem #138: do the van der Waerden numbers grow superexponentially, W(k)^(1/k) -> infinity?

Prior state unknown→proved

Theorem 1.1: there is an absolute K0K_0 with Wr(k)>kck⌊log⁡2r⌋W_r(k)>k^{ck\lfloor\log_2 r\rfloor}, c=10−5c=10^{-5}, for all k≥K0k\ge K_0 and r≥2r\ge2; hence Wr(k)1/k→∞W_r(k)^{1/k}\to\infty for each fixed rr. Prior work in 2026: Fox-Hunter proved superexponential growth for three colours, and Campos-Fox-Schildkraut proved W2(k)≥(1−o(1))k2k−1W_2(k)\ge(1-o(1))k2^{k-1}, settling W2(k)/2k→∞W_2(k)/2^k\to\infty but not the limit asked here. Not shown: the companion question…

SourceReplayReproducedFormal proofStatement auditExternal checkExpert reviewPeer review

Research memory

Claims and attempts

Scoped claims

Source authenticated

Theorem 1.1: there is an absolute K0K_0 with Wr(k)>kck⌊log⁡2r⌋W_r(k)>k^{ck\lfloor\log_2 r\rfloor}, c=10−5c=10^{-5}, for all k≥K0k\ge K_0 and r≥2r\ge2; hence Wr(k)1/k→∞W_r(k)^{1/k}\to\infty for each fixed rr. Prior work in 2026: Fox-Hunter proved superexponential growth for three colours, and Campos-Fox-Schildkraut proved W2(k)≥(1−o(1))k2k−1W_2(k)\ge(1-o(1))k2^{k-1}, settling W2(k)/2k→∞W_2(k)/2^k\to\infty but not the limit asked here. Not shown: the companion question W(k+1)−W(k)→∞W(k+1)-W(k)\to\infty, or any upper bound improvement.

Theorem 1.1: there is an absolute K0K_0 with Wr(k)>kck⌊log⁡2r⌋W_r(k)>k^{ck\lfloor\log_2 r\rfloor}, c=10−5c=10^{-5}, for all k≥K0k\ge K_0 and r≥2r\ge2; hence Wr(k)1/k→∞W_r(k)^{1/k}\to\infty for each fixed rr. Prior work in 2026: Fox-Hunter proved superexponential growth for three colours, and Campos-Fox-Schildkraut proved W2(k)≥(1−o(1))k2k−1W_2(k)\ge(1-o(1))k2^{k-1}, settling W2(k)/2k→∞W_2(k)/2^k\to\infty but not the limit asked here. Not shown: the companion question W(k+1)−W(k)→∞W(k+1)-W(k)\to\infty, or any upper bound improvement.

Recorded attempts

Evidence graph

Connected research record