The Calkin algebra, Kazhdan's property (T), and strongly self‐absorbing C∗$\mathrm{C}^*$‐algebras
Bibliographic record
Abstract
Abstract It is well known that the relative commutant of every separable nuclear ‐subalgebra of the Calkin algebra has a unital copy of Cuntz algebra . We prove that the Calkin algebra has a separable ‐subalgebra whose relative commutant has no simple, unital, and noncommutative ‐subalgebra. On the other hand, the corona of every stable, separable ‐algebra that tensorially absorbs the Jiang–Su algebra has the property that the relative commutant of every separable ‐subalgebra contains a unital copy of . Analogous result holds for other strongly self‐absorbing ‐algebras. As an application, the Calkin algebra is not isomorphic to the corona of the stabilization of the Cuntz algebra , any other Kirchberg algebra, or even the corona of the stabilization of any unital, ‐stable ‐algebra.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".