Stationary Limits of the Point Spectrum

Tom Benhamou; Hannes Jakob

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arXiv · 2610.38947

Stationary Limits of the Point Spectrum

Tom Benhamou·Hannes Jakob

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Abstract

We give an example of a directed set whose Tukey spectrum is not closed under stationary limits. This is a counterexample to a theorem due to Isbell from the 60's. We isolate a combinatorial principle arising from our example, between stationary reflection and weak compactness.

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BibTeX RIS

Tom Benhamou, Hannes Jakob. 2026-10-28. Stationary Limits of the Point Spectrum. https://arxiv.org/abs/2610.38947

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