Abstract

In this paper, we prove that the set of counterexamples to the uniform Littlewood's conjecture proposed in Bandi-Fregoli-Kleinbock, that is, the set of pairs of real numbers (x,y)(x,y) satisfying lim sup⁡Q→+∞ Q⋅min⁡1≤q≤Q⟨qx⟩⟨qy⟩>0, \limsup_{Q\to +\infty}\ Q\cdot \min_{1\leq q\leq Q}\langle qx\rangle\langle qy\rangle>0, is hyperplane absolute winning. We show that a stronger statement holds: the set of real pairs (x,y)(x,y) satisfying lim inf⁡m→+∞ Qm⋅min⁡1≤q≤Qm⟨qx⟩⟨qy⟩>0, \liminf_{m\to +\infty}\ Q_m\cdot \min_{1\leq q\leq Q_m}\langle qx\rangle\langle qy\rangle>0, is hyperplane absolute winning if Qm+1≫QmτQ_{m+1} \gg Q_m^τ for some τ>1τ> 1. In particular, the above sets have full Hausdorff dimension in R2\mathbb{R}^2. In addition, we prove that these sets are absolute winning on every regular C2C^2 planar curve whose set of points of nonzero curvature is itself absolute winning on the curve. We also establish analogous results for certain lines.

Dependence graphs

AI-generated audit

Audit summary

Audited against arXiv v2

Not a correctness certificate. A green “no issues found” result may include yellow suspected typos or minor formal issues that do not affect substantive soundness. It means this audit found no unresolved substantive error under the stated criteria; it does not replace expert scrutiny or formal verification.

Current report

Detailed mathematical audit

Generated October 24, 2026
01Statements4 reported findingsNo statement issues found

The ambient hyperplane-absolute-winning theorem, its fixed-sequence refinement, the curve and line restrictions, the homogeneous-dynamics formulations, and the two active appendix examples have compatible hypotheses and conclusions in arXiv:2608.24401v2. No false, ill-posed, or materially overstated central statement was found.

Theorem 1.2 and Corollaries 1.3–1.4No issue found

The ambient winning and full-dimension conclusions follow

PDF pp. 2–3 and 9–22 · Theorem 1.2, Corollaries 1.3–1.4, and §§3–5 · arXiv:2608.24401v2

Failure of the target inequality is covered by the dangerous rational rectangles of Lemma 3.1. The weighted attached-line and simplex lemmas concentrate every same-scale family in controlled affine-line neighborhoods, Propositions 4.1–4.2 keep their total potential within Alice's allowance, and the stage strategy eventually treats every dangerous family. Hyperplane-potential winning therefore gives HAW for EE. The zero-dimensional ordinary Littlewood exceptional set and countable-intersection stability then give both corollaries, including endpoint weights.

Theorem 1.6No issue found

Power-rapid fixed sequences give HAW intermediate sets

PDF pp. 3–4 and 22–25 · Theorem 1.6 and §6 · arXiv:2608.24401v2

The structured cubic-gap strategy treats Qm+1/Qm3→∞Q_{m+1}/Q_m^3\to\infty. If Qm+1≥cQmτQ_{m+1}\geq cQ_m^\tau with τ>1\tau>1, choosing kk with τk>3\tau^k>3 makes each residue-class subsequence cubic-gap, and EQE_{\mathbf Q} is exactly the finite intersection of the corresponding residue-class targets. HAW stability under finite intersections proves the theorem with the stated quantifiers.

Theorems 1.7–1.8No issue found

The curve and line restrictions have the claimed winning behavior

PDF pp. 4 and 25–29 · Theorems 1.7–1.8 and §7 · arXiv:2608.24401v2

On coordinate arcs, structured ambient deletions pull back to legal interval deletions unless the outcome is already outside the auxiliary dual badly approximable set. That auxiliary set is HAW by the An–Beresnevich–Velani curve theorem and the one-dimensional winning equivalence; closed derivative-exception sets are removed using Lemma 2.3. For lines, the printed exponent 2−ε2-\varepsilon is exactly the i=j=1/2i=j=1/2 case of the cited line theorem. On rational lines, convergent denominators make the relevant product tend to zero, proving the empty-intersection branch.

Theorems 1.9 and 1.11, Corollary 1.10, and Appendix ANo issue found

The dynamical translations and independence examples have the claimed scope

PDF pp. 5 and 30–35 · §1.4 and Appendix A · arXiv:2608.24401v2

The standard unipotent chart translates the ambient, weighted-ray, and curve results to the stated torus. In Appendix A, the complement of the one-dimensional Sierpiński gasket is not ambient HAW but is HAW on every curve in the theorem's class, while the pullback of R×Bad\mathbb R\times\mathrm{Bad} under (x,y)↦(x,y−f(x))(x,y)\mapsto(x,y-f(x)) is ambient HAW and misses a nonzero-curvature level curve. These give the two advertised directions of independence.

02Proofs6 reported findingsNo proof issues found

All central internal arguments close in the current version. The audit checked the dangerous-set decomposition, multiweight determinant bounds, both potential estimates, trigger-time strategy, cubic and residue-class deductions, the full curve-transfer chain, the two line cases, and both active appendix constructions. No proof gap requiring a repair was found.

Lemmas 3.1–3.6No issue found in the reviewed proof

The dangerous-set decomposition and simplex bounds preserve the required inequalities

PDF pp. 9–14 · §3 · arXiv:2608.24401v2

The product inequality is divided into the interior weighted rectangles and the two coordinate strips, with the cutoff term handled separately. Primitive attached lines have the printed coefficient bounds. For rational points in one scale cell, the relevant incidence determinant is an integer of absolute value less than one and hence vanishes; weight symmetry and the strip cross-product argument cover the remaining cases. The resulting one- or two-line neighborhoods have exactly the radii used later.

Propositions 4.1–4.2 and §5No issue found in the reviewed proof

The potential budgets and stage strategy are legal

PDF pp. 15–22 · §§4–5 · arXiv:2608.24401v2

The denominator and height partitions cover every dangerous set and have finite active cells. The line-neighborhood radii form geometric sums with the required decay, and the choices of RR, η\eta, and the cutoffs put each contribution inside Alice's budget. The trigger index is unique at a turn, all finite-height families are eventually triggered when Bob's radii shrink, and nesting transports each deletion to the stage endpoint. Thus every non-default outcome lies in EE.

Lemma 6.2 and proof of Theorem 1.6No issue found in the reviewed proof

The structured strategy retains the coefficient control needed on curves

PDF pp. 23–25 · Lemma 6.2 and proof of Theorem 1.6 · arXiv:2608.24401v2

The strategy makes r ξ(L)∣AB∣r\,\xi(L)|AB| arbitrarily small by choosing the auxiliary parameter before play. The attached-line inequalities ∣AB∣≤q|AB|\leq q and qξ(L)<Rj+1q\xi(L)<R^{j+1} give the displayed uniform control for every deleted tube. The next cubic scale is large enough for the induction, and the residue-class intersection is exactly the original liminf target rather than merely a subset.

Lemma 2.3No issue found in the reviewed proof

The open-submanifold patching lemma is valid as stated in v2

PDF p. 8 · Lemma 2.3 · arXiv:2608.24401v2

The lemma assumes that M′⊂MM'\subset M is closed, so M∖M′M\setminus M' is an open manifold on which the restricted game is defined. Intersection with the HAW complement and upward closure give one implication, while restriction gives the converse. The exceptional zero sets used in §7 are explicitly closed, so every application satisfies the lemma.

Lemmas 7.1–7.5No issue found in the reviewed proof

The ambient-to-curve transfer closes with the stated constants

PDF pp. 25–29 · §7 · arXiv:2608.24401v2

When the derivative of AX+BY+CAX+BY+C is large, the mean-value theorem confines a tube pullback to an interval of radius 22r/m2\sqrt2r/m. If it is small, regularity forces ∣AB∣>ξ2m/(2M)|AB|>\xi^2m/(2M), and the structured coefficient estimate makes every tube point leave DcD_c. Shadow balls are nested and legal; choosing 4Mβ~/m≤β4M\widetilde\beta/m\leq\beta gives the one-dimensional budget. Transference identifies DD with the pullback of Bad(1/2,1/2)\mathrm{Bad}(1/2,1/2).

Proof of Theorem 1.8 and Appendix ANo issue found in the reviewed proof

The line estimate and both active examples are complete

PDF pp. 29–35 · proof of Theorem 1.8 and Appendix A · arXiv:2608.24401v2

For rational a,ba,b, the convergent denominators qk′=dqkq_k'=dq_k make both coordinate errors O(1/qk+1′)O(1/q_{k+1}'), so their product times every intermediate cutoff tends to zero. The Sierpiński-gasket example combines projection rigidity, Furstenberg microsets, homogeneity, Frostman restriction, and diffuse-set winning in a consistent order. The second example is the image of a product HAW set under a C1C^1 diffeomorphism and is disjoint from the chosen graph. An extra construction present only inside an inactive source block is excluded from the public v2 audit and graph.

03Novelty0 reported findingsNo novelty concerns found

No non-novelty findings.

04Sources7 reported findingsFurther source verification needed

The direct game-theoretic, Diophantine, dynamical, curve, line, and active fractal inputs were checked in exact versions or explicit public proof-bearing fallbacks and match their uses. The recursive graph nevertheless has nine disclosed original-proof access limits: five inherited from the ordinary Littlewood dimension branch and four in the active Sierpiński projection branch. Exact downstream statements and applicability were checked, but they do not replace inspection of those original proofs.

Direct game, Diophantine, curve, and line inputsApplicable and sufficient

The selected source theorems apply with the printed hypotheses

Focal PDF pp. 2–3, 7–9, 11–14, and 25–29 · arXiv:2608.24401v2

Broderick–Fishman–Kleinbock–Reich–Weiss and Fishman–Simmons–Urbański supply the HAW closure and potential-game facts. An and Badziahin–Pollington–Velani supply the attached-line and dual transference inputs; Nesharim–Simmons includes endpoint weights. An–Beresnevich–Velani Theorems 2.1 and 1.2 give the curve and line winning results, and Badziahin–Harrap–Nesharim–Simmons gives the one-dimensional absolute-winning upgrade. Their hypotheses match the focal uses.

Littlewood and homogeneous-dynamics inputsApplicable and sufficient

The exact downstream theorems give the claimed translations

Focal PDF pp. 2–5 and 22–23 · Corollaries 1.3–1.4, Lemma 6.1, and §1.4 · arXiv:2608.24401v2

Einsiedler–Katok–Lindenstrauss supplies the zero Hausdorff dimension of ordinary Littlewood exceptions and the orbit formulation. Bandi–Fregoli–Kleinbock gives the uniform multiplicative/fiberwise-divergence correspondence, while Kleinbock gives the endpoint-inclusive weighted bounded-orbit correspondence. Their coordinate conventions agree with the focal chart up to harmless permutations.

Margulis–Tomanov inputNot independently verified exact source proof

The original measure-rigidity proof remains unverified

Recursive source branch for Einsiedler–Katok–Lindenstrauss Theorem 1.5 · arXiv:2608.24401v2

The exact downstream article restates the Margulis–Tomanov results and checks their hypotheses, supporting the focal invocation. A proof-bearing copy of the original Margulis–Tomanov article was not accessible, so its original proof was not independently verified.

Margulis and Tomanov, Journal d'Analyse Mathématique 69 (1996), 25–54 ↗
Prasad–Raghunathan and Ratner inputsNot independently verified exact source proofs

Two original proofs in the recursive compactness branch remain unverified

Recursive branch through Einsiedler–Katok–Lindenstrauss and Lindenstrauss–Weiss · arXiv:2608.24401v2

The exact downstream articles identify the compact-support and orbit-closure statements and apply them with compatible hypotheses. The proof-bearing Prasad–Raghunathan 1972 and Ratner 1991 articles remained behind official access gates; their two original proofs were not inspected.

Prasad and Raghunathan, Annals of Mathematics 96 (1972), 296–317 ↗
Dani and Moore inputsNot independently verified exact source proofs

Two older proofs in the recursive Mautner branch remain unverified

Recursive source branch through Shah 1991 and Moore 1980 · arXiv:2608.24401v2

Exact downstream versions identify and apply the required Dani 1977 and Moore 1966 statements. The original proof-bearing articles were not accessible through their official records. No statement or hypothesis mismatch was found, but those two original proofs remain unverified.

Moore, American Journal of Mathematics 88 (1966), 154–178 ↗
Sierpiński projection branchNot independently verified all exact source proofs

Four recursive originals behind projection rigidity remain access-limited

Focal PDF pp. 30–33 · Appendix A, Example 1 · chain through Shmerkin Corollary 6.3 and Hochman Theorem 1.6 · arXiv:2608.24401v2

The exact Shmerkin and Hochman Annals articles, the Käenmäki–Ojala–Rossi arXiv fallback, the Käenmäki–Rossi version of record, and the cited terminal books were inspected at the selected claims. Full recursion stops at Bourgain's implicit discretized structural theorem, Lau–Ngai Proposition 3.2, Kingman's subadditive theorem, and Esseen's Berry–Esseen estimate. Their roles are explicit downstream, but the four original proofs were not all available.

Shmerkin, Annals of Mathematics 189 (2019), 319–391 ↗
Terminal published booksApplicable and sufficient

The remaining recursive branches end at identified standard monographs

Dependency graph terminal layers · arXiv:2608.24401v2

The graph stops transparently at published books for König's lemma, Frostman's lemma, additive combinatorics, differentiation and conditional-expectation limits, ergodic limits, recurrence, and standard homogeneous-dynamics background. They are marked as terminal sources rather than presented as freshly re-audited original proofs.

Detailed audit reportFull reasoning, manuscript locations, and references.
Open report PDF ↗

Author response

Challenge an audit finding

Local workflow preview

A listed author may submit formal evidence that an audit is inaccurate. The response would be considered in a fresh AI re-evaluation; it would not edit the audit automatically.

Paper
arXiv:2608.24401v2
Authors listed
Vasiliy Neckrasov, Chengyang Wu, Bohan Yang
Audit date
October 24, 2026
  1. 01Establish identityMatch an authenticated scholarly identity to this paper.
  2. 02Submit evidenceIdentify the finding and give a formal mathematical response.
  3. 03Re-evaluateA separate agent checks the response and records a disposition.
Recommended production method

Authenticate with ORCID, then require an exact arXiv match

MathAudit should accept the identity only when ORCID OAuth authenticates the claimant's iD and this exact arXiv paper appears in arXiv's public authority feed for that iD. A matching name alone is not sufficient.

ORCID OAuth and arXiv authority-record lookup are not connected in this local prototype.

Email fallback for papers without a linked ORCID

A production fallback could send a one-time link only when the submitted address matches an independently maintained author-contact allowlist for this paper. MathAudit must return the same message for every address so the form cannot reveal which contacts are on that list.

This demonstration does not send, store, or compare the address.

Structured response preview

This form remains unavailable until production identity verification succeeds. Nothing entered here is submitted.

This panel never establishes authorship in the local prototype. A production result should be described narrowly as an authenticated ORCID match or control of a separately allowlisted author-contact mailbox.