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Subevent of Morning Session

Fretwell Building, UNC Charlotte

2026 Feb 14 from 11:00AM to 11:50AM (Eastern Time (US & Canada))

Abstract:

We generalize a result of Shelah that draws positive Ramsey-theoretic conclusions (the existence of infinite free sequences in algebras) from a “drastic” failure of the Singular Cardinal Hypothesis at $\aleph_\omega$. We show that the connection between these two apparently unrelated phenomena is topological and lifts to more general settings: Shelah’s theorem does not really need all of the machinery associated with pcf theory at $\aleph_\omega$. This allows us to obtain stronger results, and uncovers a dichotomy that may have further applications.