Time: 12:30 – 13:30

Room: Wean Hall 7201

Speaker: Bill Chen

Department of Mathematics

UCLA

Title: Can every mutually stationary sequence be tightly stationary?

Abstract: Mutual and tight stationarity are two notions of stationarity defined on certain products associated to a singular cardinal, introduced by Foreman and Magidor. Tight stationarity is closely related to the structure of scales at the singular cardinal, whereas mutual stationarity has a more mysterious, model-theoretic character. In this talk, I will investigate the question of Cummings, Foreman, and Magidor of whether every mutually stationary sequence can be tightly stationary. The main result is a model where mutual and tight stationarity are distinct everywhere (joint with Itay Neeman).