# Emanuel Reinecke: Unipotent homotopy theory of schemes

**Time: **
Wed 2023-04-26 13.15

**Location: **
Albano, Cramér room

**Participating: **
Emanuel Reinecke, MPIM Bonn

**Abstract**

In this talk, I will present a notion of unipotent homotopy theory for schemes, which is based on Toën's work on affine stacks. I will discuss some general properties of the resulting unipotent homotopy group schemes and explain how over a field of characteristic *p*>0, they often recover the unipotent completion of the Nori fundamental group scheme, *p*-adic etale homotopy groups, and Artin–Mazur formal groups. As examples, we will see computations in the case of curves, abelian varieties, and Calabi–Yau varieties. Joint work with Shubhodip Mondal.