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.