Positive consistency of Naimark's problem and a local hereditary reduction
Status Partially solved · unsolvedmath.comLLM status Open unverified
Top Open Problems unknownunknown Not reported cataloguedPartially solvedOpenStatement
Definitions and mathematical statement
Shared notation.
$\mathbb N$, $\mathbb Z$, $\mathbb Q$, $\mathbb R$, and $\mathbb C$ denote the natural numbers, integers, rationals, reals, and complex numbers, respectively. All additional parameters and hypotheses are specified in the question.Statement recorded in the supplied source.
Is the following relatively consistent with ZFC?Every C*-algebra $A$ that has a unique irreducible representation up to the unitary equivalence is isomorphic to the algebra of compact operators on some Hilbert space.
Formulation references: [S1], [S2].
Short English statement
Is the following relatively consistent with ZFC?Every C*-algebra $A$ that has a unique irreducible representation up to the unitary equivalence is isomorphic to the algebra of compact operators on some Hilbert space.
Sources
- S1 ULAM.AI and the UnsolvedMath Contributors, UnsolvedMath: A Curated Collection of Open Mathematics Problems, record 20001476 (AIM-FUNCTIONAL_ANALYSIS-0035). Catalogue attribution under CC BY 4.0. https://huggingface.co/datasets/ulamai/UnsolvedMath.
- S2 Original problem formulation and mathematical context. http://aimpl.org/settheorycstar/6/.
Statement licence: CC-BY-4.0 · Source file
Contributions 1
OpenAI claim summary for Math-2287
Manuscript 1 (family 297, 2026-09-24): The ZFC-constructed infinite-dimensional unital simple C*-algebra has all nonzero irreducible representations equivalent but is not K(H), refuting Naimark’s universal statement and therefore its proposed positive relative consistency; classical separable uniqueness forces this example to be nonseparable.
Positive consistency of Naimark's problem and a local hereditary reduction
OpenAI's claim
Within ZFC, the paper claims an infinite-dimensional simple unital C*-algebra carrying a faithful trace but only one unitary-equivalence class of nonzero irreducible representations, providing another counterexample to Naimark's problem. The cited manuscript argues for that result; its relation to this problem is specified below.Mathematical statement of the claimed result
Mathematical claim 1.
In ZFC, OpenAI claims a simple complex $C^*$-algebra $A$, infinite-dimensional and unital, admitting a faithful tracial state for which every nonzero irreducible representation lies in one unitary-equivalence class, while \[ A\not\simeq K(H)\quad\text{for every complex Hilbert space }H. \] Here $K(H)$ denotes compact operators. No separability assumption appears in the theorem, so the claim must not be read as a separable counterexample.Outline of the argument
Manuscript 1 (family 297, 2026-09-24): Reduced HNN adjunctions join selected pure-state classes using matching peaking projections while preserving unique extensions of all old pure states. Reduced-word estimates prevent unintended identifications. Dependency-closed subiterations ensure countable determination, so a recursion of length continuum-successor eventually catches every pure state without a diamond prediction principle.Formal verification
For family 297, the scope page documents the following selections. The selected ZFC construction has a faithful trace and a unique equivalence class of irreducible representations, but is a simple infinite-dimensional unital algebra rather than a compact-operator algebra. The documented statement covers the main claim of manuscript 1. Its selected declaration also covers the clause used for this problem. Comparator files: Naimark.lean. Declarations: OAI.NaimarkZFC.main.This site has not executed the Lean files or checked their dependencies. These descriptions report the scope of the linked declarations, rather than a new verification of the proofs.
Status caveat
OpenAI attributes these results to an internal model. Its release notice cautions that results lacking full formalization can contain mistakes. This site has not independently assessed the proofs; a solved label records the scope of the reported claim.Sources
- OpenAI, A counterexample to Naimark's problem in ZFC, 2026-09-24; citation key
OAI:A-counterexample-to-Naimarks-problem-in-ZFC-September-24-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: na:main. - Family 297: Lean scope.
- Comparator Naimark.json.
- Comparator Naimark.lean.
- OpenAI catalogue entry.