Diffeomorphism groups of discs

The closed n-dimensional disc is the simplest smooth compact n-manifold and yet, despite continuous efforts of geometers and topologists since the beginning of the 60s, its group of diffeomorphisms is still little understood. Over time it has become apparent that, although rooted in geometry and topology, the study of these groups is closely linked to several other areas within mathematics such as the study of the cohomology of arithmetic groups, stable homotopy theory, or the combinatorics of finite graphs.

In this talk, after a general introduction to the subject, I will outline some of these connections and survey recent breakthroughs in the study of diffeomorphism groups of discs in relation to algebraic K-theory, exotic Pontryagin classes, and graph complexes.

Zoom Meeting ID: 943 4202 1275
For password please contact Pieter Moree (moree@mpim...)