AI-led proof gives a sharp global squared-law transport bound

For any real law with X² in [A,B], A=3−√6 and B=3+√6, let δ=3(E[X²])²−E[X⁴] and let X₀ be the four-node Gaussian quadrature law identified by zero deficit. For every feasible 0≤δ≤30+12√6, W1(L(X²),L(X₀²))≤√(δ/3), using ordinary infimum-over-couplings Wasserstein distance. The bound is attained at every feasible deficit and does not require symmetry of X.

Sources for this record

What was already known

The published project record proves a sharp support-ratio criterion for symmetric sub-Gaussian laws, but does not state this full-range transport stability bound. The project also gives a separate local transport estimate.

AI involvement AI-led

JD Jones directed the project. A GPT-6 Pro consultation supplied the global affine-transport argument; Codex agents developed and formalized it, with automated internal reviews.

The disclosure credits a GPT-6 Pro consultation with the global affine-transport argument and Codex agents with integration and formal proof under JD Jones’s direction.

Importance Notable

The result gives an exact attainable W1 stability bound for every feasible deficit, including nonsymmetric laws.

Limitations

Only the squared law under the normalized support restriction is controlled; this does not bound W1 between the laws of X themselves. The reported verification run predates the cited documentation revision, which says formal sources were preserved; no human specialist review is documented.

Technical verification Formal (Lean 4/Mathlib, Comparator, NanoDa and con-ron with exact rational certificate checking)

The repository reports an exact-commit kernel run covering ordinary W1 finiteness, the global bound, the complete feasible deficit range and attaining laws. The checked commit is 51c9ea6; the pinned documentation revision says the formal payload was preserved. This review did not compare the trees or rerun the suite.

Formal checking

Source-reported exact-commit statement comparison and kernel replay at 51c9ea6; not reproduced here.

Checker
Lean 4/Mathlib, Comparator, NanoDa and con-ron
Scope
squared_transport_finiteness, global_squared_transport, fourth_deficit_range and global_transport_attainment; repository states formal payload unchanged at the cited revision
Basis
Reported by the linked checker
Evidence source

Checking a formal statement does not establish that it matches the original problem.

Human understanding Few

The disclosure documents automated internal reviews but no named human explanation of the global affine-coupling mechanism. Few is the evidence default.

Correction and publication history

2026-10-18 · publication

The result gives an exact attainable W1 stability bound for every feasible deficit, including nonsymmetric laws.

Read this published revision