Almost Affine Invariance Over Prime Fields: Green Problem 90

Jie Ma, Quanyu Tang, Max Wenqiang Xu

Ma, Tang and Xu prove that half-density subsets of Fₚ can be almost invariant under every affine map with 1≤|a|≤K and |b|≤K exactly when K=o(log p). The AI-attributed new ingredient is the q-adic valuation formulation used for the sharp upper bound.

Sources for this record

What was already known

Green asked for the threshold. Earlier amenability constructions and an upper restriction K<p^(1/100) left a wide gap.

AI involvement AI-centered

Ma, Tang and Xu credit ChatGPT 5.4 with the retained q-adic valuation formulation. They developed the final proof; the amenability idea was already known to human researchers.

The first-person disclosure identifies the retained, central valuation step as mostly AI-origin, while the surrounding proof and previously known amenability route have substantial human input.

Importance Notable

The valuation step helps identify the sharp logarithmic threshold.

Limitations

The lower construction uses a previously known amenability idea. The authors corrected faulty model drafts and developed the surrounding Fourier and probabilistic arguments. No completed check of the final valuation proof is documented.

Technical verification Reported

The paper presents proofs and notes iterative correction of AI errors, but no completed human or machine check of the final q-adic upper-bound argument is expressly documented. Green's comments improved the writing and prior-work context, not a stated proof audit.

Human understanding Full

The human authors explain Fourier concentration, approximate dilation invariance, the valuation sum and the lower Følner construction, including where early model arguments had gaps.

Correction and publication history