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Must a closed manifold admitting a metric without conjugate points admit a metric of nonpositive curvature?

Theorem 1.1: there is a closed connected orientable smooth 3-manifold with a smooth metric without conjugate points that admits no smooth metric of nonpositive sectional curvature. The manifold glues two copies of (punctured torus) x S1S^1 by Leeb's obstructed gluing; π1\pi_1 admits no proper cocompact action on a CAT(0) space, so there is no locally CAT(0) metric, and by Ivanov-Kapovitch no metric without focal points. Not shown: higher-dimensional examples, or an answer to Ivanov-Kapovitch's other questions about fundamental groups.

Exact FrontierDelta

Prior state unknown→disproved

Scope and record

Occurred: Sep 24, 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: Must a closed manifold admitting a metric without conjugate points admit a metric of nonpositive curvature? · No conjugate points vs nonpositive curvature

Confidence: Not scored

Registry verification: lean checked · announcement · candidate

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Attribution

VibeMathed
registry · event recorded by

Unreleased internal OpenAI model
model · ai model contributor · OpenAI

Artifacts and verifiers

Lean formalization (ConjugatePoints three-manifold)

lean artifact · pending

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Lineage and corrections

Must a closed manifold admitting a metric without conjugate points admit a metric of nonpositive curvature? parent of this event

Theorem 1.1: there is a closed connected orientable smooth 3-manifold with a smooth metric without conjugate points that admits no smooth metric of nonpositive sectional curvature. The manifold glues two copies of (punctured torus) x S1S^1 by Leeb's obstructed gluing; π1\pi_1 admits no proper cocompact action on a CAT(0) space, so there is no locally CAT(0) metric, and by Ivanov-Kapovitch no metric without focal points. Not shown: higher-dimensional examples, or an answer to Ivanov-Kapovitch's other questions about fundamental groups. parent of this event

This event attributed to Unreleased internal OpenAI model

Must a closed manifold admitting a metric without conjugate points admit a metric of nonpositive curvature? evidence for this event

Lean formalization (ConjugatePoints three-manifold) evidence for this event

VibeMathed record: Must a closed manifold admitting a metric without conjugate points admit a metric of nonpositive curvature? evidence for this event

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