I will talk about the theory of weak* sequential closures
(weak* derived sets), which S. Banach and S. Mazurkiewicz started to
develop in 1929-1932. I plan to describe the history of the topic and
its applications. The main new result: for every nonreflexive Banach
space X and every countable successor ordinal α, there exists a convex
subset A in X* such that α is the least ordinal for which the weak*
derived set of order α coincides with the weak* closure of A. This
result extends the previously known results on weak* derived sets by
Ostrovskii (2011) and Silber (2021).
The talk will be available under the link
Topic: Online Functional Analysis Seminar at IMPAN
Time: JAN 18, 2022 03:00 PM Warsaw