Stefan Witzel
Stefan Witzel

My research interests fall into the area of geometric group theory. That is, I study groups as coarse geometric objects. I am particularly interested in lattices on buildings, such as arithmetic groups and Kac-Moody groups. Other classes of groups I am interested in are relatives of Thompson's groups F, T and V and Artin groups. Many of these groups act on non-positively curved spaces, although often not cocompactly.

I am currently (January till June 2019) working at École Polytechnique as a Feodor-Lynen Fellow of the Humboldt Foundation. After that I will return to Germany as a member of the DFG Heisenberg Programme.

Previously I have been in Bielefeld as a PostDoc, in Münster as a PostDoc, in Darmstadt as a (PhD-)student, and in Bordeaux as an Erasmus student.

My student Eduard Schesler works on Sigma-invariants of S-arithmetic subgroups of Borel groups.

I was one of the organizers of the conferences Topological and Homological Methods in Group Theory and Topological and Homological Methods in Group Theory 2018.


Centre de Mathématiques Laurent Schwartz
École polytechnique
F-91128 Palaiseau cedex

Office: 06 1015
Phone: +33 9 80 76 45 95
Email: switzel [at]

Last modified: Mon 11 Feb 2019, 11:38