VibeMathedMath problems solved by AI

Kotzig's Perfect 1-Factorisation Conjecture, Asymptotically

Kotzig conjectured that for every even n4n \ge 4 the complete graph KnK_n decomposes into n1n-1 perfect matchings such that every pair of them forms a Hamilton cycle. An asymptotic version holds: KnK_n decomposes into n1n-1 perfect matchings of which (1o(1))n(1-o(1))n have the property that any pair forms a Hamilton cycle.

Result
Proved(see note)
Status
Partial result
AI contribution
AI-assisted
Method
Construction
Field
Design theory
Posed by
Anton Kotzig
Year posed
1964
Years open
62y
Solved
2026-07-10
Model
ChatGPT 5.4
Vendor
OpenAI
Collaborators
Yangyang Cheng, Amedeo Sgueglia
Verification
Unreviewed
Publication
Preprint
Significance
30 / 100
Disclosed cost
Wikipedia
No dedicated article

What was actually shown

asymptotic form only; Kotzig's conjecture itself remains far from solved

What the AI did

The authors state that the construction in Theorem 1.3, a generalisation of the one in their introduction, was generated by ChatGPT 5.4, which also supplied a correct but long proof of it. The proof they present is a cleaner and substantially different one of their own, and the proof of the main theorem, Theorem 1.2, was obtained entirely by the authors. The model's construction is nonetheless load-bearing: the main result is built by deleting a random subset of the matchings it produces.

Verification

arXiv preprint that routes through a robust-expander result of Kuhn and Osthus; not yet peer-reviewed.

Source

arXiv:2607.09459 - The perfect 1-factorisation conjecture holds asymptotically

Discussion