VibeMathedMath problems solved with AI

Naor's sublinear-dimension question for finite subsets of Lp, 1 < p < infinity, p not 2

The Johnson-Lindenstrauss lemma embeds every nn-point subset of Hilbert space into O(log⁡n)O(\log n) dimensions with distortion 1+ε1+\varepsilon, and Johnson and Lindenstrauss (1984, Problem 3) asked what analogues hold in other Banach spaces. In L1L_1 polynomial dimension is necessary (Brinkman-Charikar), and Ball's exact bound for LpL_p is (n2)\binom n2 coordinates. Naor (ICM 2018) remarked that for no fixed p∈[1,∞)∖{2}p\in[1,\infty)\setminus\{2\} was it even known whether every nn-point subset of ℓp\ell_p embeds with bounded distortion into a normed space of dimension o(n)o(n). For fixed p≠2p\ne2 and distortion DD, can every nn-point subset of LpL_p be embedded with distortion DD in dimension o(n)o(n)?

Result
Proved(see note)
Status
Candidate (review pending)
AI contribution
AI-discovered
Method
Argument
Field
Metric embeddings, Banach space geometry
Posed by
Assaf Naor (after William B. Johnson and Joram Lindenstrauss)
Year posed
2018
Years open
8y
Solved
2026-09-23
Model
Unreleased internal OpenAI model
Vendor
OpenAI
Collaborators
—
Verification
Lean-checked, statement unaudited
Publication
Announced
Collection
OpenAI math release (October 2026), version adc7f12
Significance
35 / 100
Disclosed cost
—
Wikipedia
No dedicated article

What was actually shown

Theorem 1.1: for fixed 1<p<∞1<p<\infty, p≠2p\ne2, and D>1D>1, every nn-point subset of any LpL_p embeds with distortion DD into ℓpd\ell_p^d (same exponent, coordinate target, nonlinear map) with d≤exp⁡(Cp,D(log⁡n)γ(p))=no(1)d\le\exp(C_{p,D}(\log n)^{\gamma(p)})=n^{o(1)}, where γ(p)=2−p\gamma(p)=2-p for p<2p<2 and 1−2/p1-2/p for p>2p>2; exact embeddings need dimension of order n2n^2. This answers the o(n)o(n) question for every p∈(1,∞)∖{2}p\in(1,\infty)\setminus\{2\}. Not shown: p=1p=1; Naor's Question 13 itself (O(log⁡n)O(\log n) dimension in some normed space), which Naor-Ren's 2026 lower bound already excludes for ℓpd\ell_p^d targets when p>2p>2; optimal exponents; an efficient algorithm.

What the AI did

The release README says the results were produced by an unreleased internal OpenAI model with a fixed procedure, on average about three hours of ChatGPT Pro thinking compute per result, and that some outputs build on earlier model results. This result is not among the README's exceptions (the Hodge conjecture for CM abelian varieties and the Re(s) > 11/12 zero-free region). The manuscripts are authored 'OpenAI' and name no human author. The single manuscript (September 23, 2026) is the whole family.

Verification

No independent mathematician has checked this yet. Checked here: the abstract, introduction and Theorem 1.1 were read against Naor's remark (read in the ICM text) and Johnson-Lindenstrauss Problem 3. The proof (weighted-moment distributions by convex separation, electrical-flow localization, stable and signed Poisson increments, Maurey sampling) was not refereed. lean/formalization.yaml lists comparator SubpolynomialLp, declaration OAI.SubpolynomialLp.source_main (file OAI/Analysis/LpDimension/Main.lean). Its statement was read here: with dp(n,D)d_p(n,D) the least dd such that every injective nn-point family in any Lp(μ)L_p(\mu) embeds into ℓpd\ell_p^d with distortion DD, for 1<p1<p, p≠2p\ne2 and each D>1D>1 there is CC with log⁡n/log⁡(1+2D)≤dp(n,D)≤exp⁡(C(log⁡n)γ(p))\log n/\log(1+2D)\le d_p(n,D)\le\exp(C(\log n)^{\gamma(p)}); at D=1D=1, ⌊(n−1)/4⌋2≤dp(n,1)≤(n2)\lfloor(n-1)/4\rfloor^2\le d_p(n,1)\le\binom n2 for n≥9n\ge9; and the log-ratio tends to 0 or 2. That states the headline. Not rebuilt here. Permitted axioms: propext, Quot.sound, Classical.choice.

Sources

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