Introduction to Topological Stacks Seminar 

27/06/2006, 10:30 — 11:30 — Room P3.10, Mathematics Building
Behrang Noohi, Max Planck Institute, Bonn

Introduction to Topological Stacks II.

In these lectures we will introduce topological stacks and explain how classical homotopy theory can be extended to the setting of topological stacks. We motivate this by showing that each of the following classes of objects naturally gives rise to a class of topological stacks: orbifolds; graphs of groups and, more generally, complexes of groups; Artin stacks over the complex numbers; topological spaces with a group action; differential groupoids; foliated manifolds. In particular, homotopy theory of topological stacks can be applied in all these situations in a unified manner. We show how certain general results about topological stacks specialize to well-known or new, results in each of these theories.