Confinement schemas and the reach of block certificates for powers of rational numbers modulo one

Ralf Stephan

For every nonzero real ξ, the fractional parts of ξ(3/2)ⁿ cannot all lie in the closed interval [2/7,5/7]. Equivalently, ||ξ(3/2)ⁿ||<2/7 infinitely often. The certificate has depth 15 and 166 blocks across 32 rank strata.

Sources for this record

What was already known

An earlier certificate corpus reached a single-window length about 0.40722, and Dubickas printed a 31/81 exclusion. The new interval has length 3/7≈0.42857; Dubickas’s 2006 nearest-integer constant is slightly stronger than 2/7.

AI involvement AI-led

Stephan chose the target and checked statements; the disclosure credits Claude Fable 5 with the discovery and draft and Claude Opus 5 with the Lean formalization.

The source explicitly assigns mathematical discovery to Claude Fable 5 and formal proof work to Claude Opus 5 under Stephan's direction.

Importance Notable

Extends the certified single-window exclusion for powers of 3/2.

Limitations

This does not resolve Mahler’s length-1/2 problem. The paper’s certificate-format and escape-time results are separate claims.

Technical verification Formal (Lean 4 kernel exact integer certificate, Comparator and exported-proof replay)

The four Theorem E forms are among the 14 compared declarations. The cited source reports Lean kernel evaluation of the raw exact integer certificate, Comparator statement matching and exported-proof replay. This review did not rerun the checker; search-only larger records are outside the assessed claim.

Formal checking

Challenge2/Solution2 comparison and kernel reduction of certTwoSeven.ok from raw integer data

Checker
Palomar Comparator and Lean kernel
Scope
Theorem E's closed [2/7,5/7] exclusion, eventual escape and infinitely-often nearest-integer forms for every nonzero real ξ
Basis
Reported by the linked checker
Evidence source

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

Human understanding Few

Stephan checked statements and authored the paper, but credits the mathematical discovery and drafting to AI; no named human explanation of the rank-stratified certificate mechanism is documented. Few is the missing-evidence default.

Correction and publication history