Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
Updated
Claim. Write for the minimum, over signs , of ; Parseval's identity gives . Theorem 1.1 of OpenAI, Asymptotically minimal maxima of real Littlewood polynomials, OpenAI Math Release preprint, 23 September 2026, at the pinned revision of the release repository (the preprint link), states that : for every there is such that every integer admits signs with
The manuscript is paged at the result page of its card. Real signs are coefficients of modulus one, so this refutes the constant asked for in Problem 230: given , take and , and put for ; the site's polynomial is times the sum above, has the same modulus on the circle, and its maximum is at most . The site's question was already answered no by Kahane with complex unimodular coefficients, and this is a second route with coefficients from the smaller class , so the same theorem answers the real-sign question of Problem 1150 negatively; that problem's page is the place for that claim. The theorem is one-sided and existential: it gives no lower bound for , no convergence rate and no signing algorithm, and the manuscript notes that Erdélyi's additive gap is compatible with it. The proof first builds relaxed coefficients in with small defect from signs by sampling quadratic-phase waves off a real trigonometric polynomial on an auxiliary torus, packing their Fourier supports with the Pippenger--Spencer coloring theorem, then rounds them to signs with a defect-sensitive discrepancy bound, using the partial-coloring method of Beck and Spencer in the arbitrary-vector form verified through the theorem of Lovett and Meka (Sections 2--6). The same manuscript derives unbounded binary merit factors through all lengths, a uniquely ergodic binary Morse shift with simple spectrum whose zero-coordinate spectral measure is absolutely continuous ( density), and flatness for every finite , and its Appendix A disputes nonflatness claims in preprints of el Abdalaoui; none of these is part of this claim. Two later release manuscripts of 5 October 2026 strengthen the construction without Lean: Nearly minimal maxima and positive minima of Littlewood polynomials (Theorem 1.1 of its card) adds the lower bound to the same upper bound, and Ultraflat real Littlewood polynomials (Theorem 1 of its card) states that for every and every large some signs give on the whole circle, the points included, a real-sign ultraflat family stronger than the constant-factor flatness of Problem 228. Those two statements are recorded here as the same claimant's unformalized companions; the accepted claim is Theorem 1.1 of 23 September.
Formalization. The release's Lean tree (folder lean/ at the pinned
revision, with the release's pinned Lean and Mathlib) proves
OAI.AsymptoticallyMinimalLittlewood.main : MainStatement in
OAI/Analysis/Littlewood/Main.lean, where the comparator challenge
ComparatorChallenges/AsymptoticallyMinimalLittlewood.lean defines
def littlewoodValue {N : ℕ} (ε : Fin N → ℝ) (z : ℂ) : ℂ :=
∑ k : Fin N, (ε k : ℂ) * z ^ (k : ℕ)
def IsRealSigning {N : ℕ} (ε : Fin N → ℝ) : Prop :=
∀ k, ε k = -1 ∨ ε k = 1
def MainStatement : Prop :=
∀ η : ℝ, 0 < η → ∃ N₀ : ℕ, 1 ≤ N₀ ∧ ∀ N : ℕ, N₀ ≤ N →
∃ ε : Fin N → ℝ, IsRealSigning ε ∧
∀ z : ℂ, ‖z‖ = 1 → ‖littlewoodValue ε z‖ ≤ (1 + η) * Real.sqrt Nand its configuration AsymptoticallyMinimalLittlewood.json pins the
declaration OAI.AsymptoticallyMinimalLittlewood.main (its
definition_names list is empty) and permits only the axioms propext,
Quot.sound and Classical.choice; the release's catalog
lean/formalization.yaml lists the declaration under this manuscript, and
the release's family note pairs it with a second comparator,
LittlewoodFiniteFlatness.lean, for the statement, which is not part
of this claim. The bridge from the declaration to the site's question, the
factor , the passage from the pointwise bound to the maximum and the
choice with , is elementary and is not in Lean.
Depends on. Nothing in this wiki: the proof is self-contained in the
manuscript and its Lean tree, and the Lean statement rests on Mathlib's
finite sums, complex norm and Real.sqrt alone.
Acceptance. A disproof of Problem 230 with real coefficients; its Lean
declaration was built here with the three standard axioms and its statement
audited here for fidelity. Formalized: this corpus's verification built the
solution module and the comparator challenge from the release at the pinned
revision, printed the axioms of the declaration, which were exactly propext,
Classical.choice and Quot.sound, and found the comparator fingerprint of
the pinned challenge statement identical to the solution's; the result was
recorded on 2026-10-07. The statement audit that formalized requires is this
corpus's own: a statement-fidelity audit unfolded
littlewoodValue and IsRealSigning, compared the declaration with the
problem page's Statement (the coefficient class, the index range, the circle,
the bound and the quantifiers over and ) and judged that it refutes the
question through the elementary bridge above. Not reviewed: no outside reviewer
or independent acceptance of this route is recorded; the site's commentary
credits Kahane and does not mention the release (the proof-claims tab was empty
on 2026-10-07). Not refereed: the manuscripts are unrefereed release preprints
with no arXiv version, whose author line names OpenAI; the release's README
says that its manuscripts and proof artifacts were produced by an internal
OpenAI model and that the collection includes results at different stages of
verification. This page describes the pinned revision of the release only.