Dávid Kunszenti-Kovács, Tübingen University (Germany): The Jacobs-deLeeuw-Glicksberg decomposition and ergodic theorems

Dávid Kunszenti-Kovács, Tübingen University (Germany) will give a talk with title "The Jacobs-deLeeuw-Glicksberg decomposition and ergodic theorems".

Abstract: We present the classical decomposition theorem for contractions on Hilbert spaces due to Jacobs, deLeeuw and Glicksberg, and show how it can be used to prove ergodic theorems. We then prove a new version of this decomposition, adapted to the context of W*-algebras, with consequences for W*-dynamical systems. Finally we take a look at how the characterizations given in the original decomposition theorem can be further strengthened.