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The transitive algebra problem

Corollary 1.2 of the principal manuscript: the commutant of the constructed nonzero quasinilpotent operator SS is a proper, strongly closed, unital, transitive complex algebra, so it is not strongly dense in B(H)B(H). This answers the question negatively on every infinite-dimensional separable Hilbert space. It is an immediate consequence of the hyperinvariant counterexample, since the commutant of an operator without hyperinvariant subspaces is transitive. The algebra is a commutant, so nothing is said about singly generated transitive algebras, which is the invariant subspace problem.

Exact FrontierDelta

Prior state unknown→disproved

Scope and record

Occurred: Sep 27, 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: The transitive algebra problem · Transitive algebra problem

Confidence: Not scored

Registry verification: lean checked · announcement · candidate

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Attribution

VibeMathed
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Unreleased internal OpenAI model
model · ai model contributor · OpenAI

Artifacts and verifiers

Lean Comparator challenge BackwardIntertwiners (OpenAI math release)

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Lean Comparator challenge BackwardIntertwiners (OpenAI math release) evidence for this event

VibeMathed record: The transitive algebra problem evidence for this event

This event attributed to Unreleased internal OpenAI model

Corollary 1.2 of the principal manuscript: the commutant of the constructed nonzero quasinilpotent operator SS is a proper, strongly closed, unital, transitive complex algebra, so it is not strongly dense in B(H)B(H). This answers the question negatively on every infinite-dimensional separable Hilbert space. It is an immediate consequence of the hyperinvariant counterexample, since the commutant of an operator without hyperinvariant subspaces is transitive. The algebra is a commutant, so nothing is said about singly generated transitive algebras, which is the invariant subspace problem. parent of this event

The transitive algebra problem parent of this event

Backward intertwiners and a transitive commutant (companion) evidence for this event

Arveson 1967, A density theorem for operator algebras evidence for this event

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