EVENT DETAILS AND ABSTRACT

Title: Cogroupoid structures on the circle and the Hodge degeneration
Speaker: Tasos Moulinos
Speaker Info: Toulouse
Brief Description:
Special Note:
Abstract:

In this talk I will describe recent work which expresses the Hodge degeneration between de Rham and Hodge cohomology as a delooping of the filtered loop space E_2 groupoid. I will explain what these terms mean and will describe how this groupoid arises from viewing the circle S^1 as an iterated cogroupoid in topological spaces. As I will explain, this is a stronger bit of structure than the more commonly studied pinch map on S^1. Time permitting I will describe how Todd classes for smooth and proper schemes emerge out of the this filtered loop space story, as well as describe implications for Hochschild cohomology.