The Auslander-Reiten conjecture for Artin algebras
Let be an Artin algebra (for example a finite-dimensional algebra over a field) and a finitely generated -module. Auslander and Reiten (1975), in their work on the generalized Nakayama conjecture, conjectured that must be projective if for every . It was proved for many classes (complete intersections, radical cube zero, Igusa-Todorov algebras, rings satisfying Auslander's condition), and Schulz's non-projective module without self-extensions lives over a skew field, outside this setting. The Gorenstein-projective conjecture (Luo-Huang) is its restriction to Gorenstein-projective modules. Is every finitely generated module over an Artin algebra with for all projective?
- Result
- Disproved(see note)
- Status
- Candidate (review pending)
- AI contribution
- AI-discovered
- Method
- Construction
- Field
- Representation theory of algebras; homological conjectures
- Posed by
- Maurice Auslander and Idun Reiten, On a generalized version of the Nakayama conjecture (Proc. AMS, 1975)
- Year posed
- 1975
- Years open
- 51y
- 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
- 45 / 100
- Disclosed cost
- —
- Wikipedia
- No dedicated article
What was actually shown
Claims Theorem 1.1: over there are a finite-dimensional triangular algebra with eight simple modules and , and a finite-dimensional nonprojective Gorenstein-projective module with for all , persisting under every field extension (so also over an algebraically closed field of characteristic two). This disproves the Auslander-Reiten and Gorenstein-projective conjectures; also refutes the generator form. It does NOT touch the commutative Noetherian form of the conjecture, and gives no example in characteristic zero.
What the AI did
The release README says the manuscripts were produced by an unreleased internal OpenAI model, the vast majority by one fixed procedure using on average about three hours of ChatGPT Pro thinking compute per result, and that some outputs build on earlier results produced by the models. Its named exceptions to that procedure (the zeta zero-free region work, whose Re(s) > 11/12 write-up was human edited, and the Hodge conjecture for CM abelian varieties) do not concern this family. Both manuscripts of the family are credited to OpenAI with no human author named. The two counterexamples share a ten-dimensional starting algebra; each manuscript states it contains its own complete proof.
Verification
No independent mathematician has checked this yet. Theorem 1.1 was read against the conjecture as posed: an explicit finite-dimensional algebra over with a nonprojective module satisfying the vanishing for every . formalization.yaml lists ComparatorChallenges/AuslanderReiten.json, declaration OAI.ArExplicit.Statement.main, file OAI/Algebra/AuslanderReiten/All.lean. The statement was read here: algebraically independent over , and a finite-dimensional algebra with a finite-dimensional module that is not projective, is a cokernel in a totally acyclic complex of finite projectives, has vanishing positive Ext into itself and into the algebra, has semisimple quotient and nonzero fourth radical power, and keeps all of this after base change to every field extension. That is the headline claim, including the Gorenstein-projective form. Permitted axioms are propext, Quot.sound and Classical.choice. Not rebuilt here.
Sources
- PaperCompanion: A counterexample to Tachikawa's second conjecture
- Lean proofLean: Auslander-Reiten counterexample (formalization.yaml file)Lean comparator statement: Auslander-Reiten counterexample
- CodeOpenAI math release: An explicit counterexample to the Auslander-Reiten conjecture
- Problem recordAuslander and Reiten (1975), On a generalized version of the Nakayama conjecture
- OtherThe equivalence of Tachikawa's second conjecture and Auslander-Reiten