# Thomas Blom: Homotopy theory of groupoids

**Time: **
Fri 2019-02-15 13.00 - 14.00

**Lecturer: **
Thomas Blom

**Location: **
Room 22, building 5, Kräftriket, Department of Mathematics, Stockholm University

As an algebraic topologist, I often find myself in the situation where I consider certain objects (e.g. certain topological spaces) as equivalent, even though they are not isomorphic. More specifically,

here may exist a map between two such objects that preserves all the structure that I am interested in, even though it is not an isomorphisms. Much of (mordern) homotopy theory is concerned with

finding ways to deal with this.

In this talk, I will give some examples of such situations. I will discuss one of these examples, namely groupoids, in more detail. If time permits, I will also say something about profinite groupoids, which are one of the main objects that I studied in my master's thesis.