Source authenticated

Ryser's conjecture on covers of r-partite hypergraphs

Ryser's conjecture is false, already for intersecting hypergraphs. September 23: for every sufficiently large prime s≡2(mod3)s\equiv2\pmod3 and every sufficiently large odd nn (threshold depending on ss), there is an intersecting (sn+1)(s^n+1)-partite (sn+1)(s^n+1)-uniform hypergraph with τ=sn+1\tau=s^n+1, against the conjectured sns^n. September 27: for every sufficiently large prime qq, an intersecting (q+1)(q+1)-partite (q+1)(q+1)-uniform hypergraph with τ=q+1\tau=q+1 and exactly q+1q+1 nonisolated vertices in each part. Not given: an explicit rank or example, or anything for small rr (cases r=4,5r=4,5 remain open in general).

Exact FrontierDelta

Prior state unknown→disproved

Scope and record

Occurred: Sep 23, 2026

Delta type: SOURCE CLAIM

Assumptions: VibeMathed verification: lean-checked. Publication: announcement. AI contribution: ai-discovered. VibeMathed editorial classifications, scores, notes, relations, and dataset structure are CC BY 4.0. Source statements and linked content retain their own rights.

Canonical aliases: Ryser's conjecture on covers of r-partite hypergraphs · Ryser's conjecture

Confidence: Not scored

Registry verification: lean checked · announcement · candidate

Open the source record ↗

Attribution

VibeMathed
registry · event recorded by

Unreleased internal OpenAI model
model · ai model contributor · OpenAI

Artifacts and verifiers

Lean proof: OAI/Combinatorics/Ryser/Construction/Main.lean

lean artifact · pending

Artifact ↗
Lean proof: OAI/Combinatorics/Ryser/OddExtensions.lean

lean artifact · pending

Artifact ↗
Lean proof (balanced companion): OAI/Combinatorics/BalancedRyser/Main.lean

lean artifact · pending

Artifact ↗

Compute record

No linked compute attempts recorded.

Lineage and corrections

Companion: Balanced counterexamples to Ryser's conjecture at prime orders (September 27, 2026) evidence for this event

This event attributed to Unreleased internal OpenAI model

VibeMathed record: Ryser's conjecture on covers of r-partite hypergraphs evidence for this event

Lean proof: OAI/Combinatorics/Ryser/OddExtensions.lean evidence for this event

Best and Wanless, What did Ryser conjecture? (arXiv:1801.02893) evidence for this event

Ryser's conjecture on covers of r-partite hypergraphs parent of this event

Gyarfas's conjecture on covering edge-colored complete graphs by r-1 monochromatic trees evidence for this event

Ryser's conjecture is false, already for intersecting hypergraphs. September 23: for every sufficiently large prime s≡2(mod3)s\equiv2\pmod3 and every sufficiently large odd nn (threshold depending on ss), there is an intersecting (sn+1)(s^n+1)-partite (sn+1)(s^n+1)-uniform hypergraph with τ=sn+1\tau=s^n+1, against the conjectured sns^n. September 27: for every sufficiently large prime qq, an intersecting (q+1)(q+1)-partite (q+1)(q+1)-uniform hypergraph with τ=q+1\tau=q+1 and exactly q+1q+1 nonisolated vertices in each part. Not given: an explicit rank or example, or anything for small rr (cases r=4,5r=4,5 remain open in general). parent of this event

Lean proof (balanced companion): OAI/Combinatorics/BalancedRyser/Main.lean evidence for this event

Lean proof: OAI/Combinatorics/Ryser/Construction/Main.lean evidence for this event

Act on this frontier

Verify, challenge, or extend the result.

Ryser's conjecture on covers of r-partite hypergraphs — Mathematical Frontier Network