Activities This Week

A C*-algebra is said to be K-stable if its nonstable K-groups are naturally isomorphic to the usual K-theory groups. In this talk, we shall study continuous C(X)-algebras, each of whose fibers are K-stable. We will show that such an algebra is itself K-stable under the assumption that the underlying space X is compact, metrizable, and of finite covering dimension.

Recurrence is a classical topic in ergodic theory and dynamical systems, which goes back to Poincaré’s recurrence theorem. I will talk about old, less old, and new results on recurrence. In particular, I will talk about how to obtain asymptotic results on the number of times a typical point returns to a shrinking neighbourhood around itself.