Fields institute, Room 210
Speaker: Martino Lupini
Talk Title: The descriptive set theory of Polish groupoids
Abstract: I will present an overview of functorial classification within the framework of invariant descriptive set theory, based on the notion of Polish groupoid and Borel classifying functor. I will then explain how several results about Polish group actions admit natural generalizations to Polish groupoids, extending works of Becker-Kechris, Effros, Hjorth, and Ramsay.