The periodic tiling conjecture in dimension three
A finite nonempty is a translational tile if for some ; the tiling is periodic if is invariant under a finite-index subgroup. The periodic tiling conjecture (Lagarias and Wang, 1996, also in a Euclidean form for bounded measurable tiles of ) asserts that every translational tile admits a periodic tiling. It holds in (Newman) and (Bhattacharya), and Greenfeld and Tao disproved it in sufficiently high dimension. Does every finite translational tile of , and every bounded tile of , admit a periodic tiling?
- Result
- Disproved(see note)
- Status
- Candidate (review pending)
- AI contribution
- AI-discovered
- Method
- Construction
- Field
- Translational tilings of lattices and Euclidean space
- Posed by
- Jeffrey C. Lagarias and Yang Wang
- Year posed
- 1996
- Years open
- 30y
- 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
- 38 / 100
- Disclosed cost
- —
- Wikipedia
- No dedicated article
What was actually shown
Theorem 1.1: there is a finite nonempty that tiles by translations, but no translation set of a tiling is invariant under a finite-index subgroup; and tiles up to null sets, with no tiling whose translation set is invariant under a full-rank lattice, even allowing real translations. With Bhattacharya's planar theorem, three is the least lattice dimension where periodic tiling fails. The tile is not claimed to be connected, and the result concerns full periodicity only, not the absence of every individual period.
What the AI did
The release README says every result in it was produced by an unreleased internal OpenAI model following 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 manuscript is authored 'OpenAI' and names no human author. Single-manuscript family dated September 23, 2026. The paper says it follows the Sudoku strategy of Greenfeld and Tao and adds a new encoding keeping the finite factor cyclic.
Verification
No independent mathematician has checked this yet. Checked here: Theorem 1.1 was read against the conjecture; it gives a finite tile of that tiles but admits no fully periodic tiling, and its unit-cube thickening has the same property in with arbitrary real translations. lean/formalization.yaml lists a main result for this manuscript (comparator PeriodicTilingThree, declaration OAI.PeriodicTilingThree.periodic_tiling_counterexample_and_minimality). The comparator statement was read here: it asserts a nonempty finite with a tiling and no finite-index-invariant tiling, an almost-everywhere tiling of by its thickening with no tiling invariant under a full-rank lattice, and that 3 is the least admitting such a lattice tile. This states the headline claim, plus minimality. Not rebuilt here. Permitted axioms: propext, Quot.sound, Classical.choice.
Sources
- Lean proofLean proof (OAI.PeriodicTilingThree.periodic_tiling_counterexample_and_minimality)Comparator statement: PeriodicTilingThree.lean
- CodeOpenAI math release: A translational tile with no fully periodic tiling in dimension three
- Problem recordGreenfeld and Tao, A counterexample to the periodic tiling conjecture (high dimension)