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 Heisenberg professor at JLU Gießen. In the past I have been working

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

I am one of the organizers of the conference series Topological and Homological Methods in Group Theory. The 2020 edition THGT 20 was cancelled due to the SARS-Cov-2 pandemic. The past editions took place in 2016 and 2018.



Faculty of Mathematics
Bielefeld University
Universitätsstraße 25
D-33615 Bielefeld

Office: V4-215
Fax: +49 521 106 6480
Email: switzel [at]


Mathematical Institute
Gießen University
Arndtstr. 2
D-35392 Gießen

Office: 5
Phone: +49 641 99 32080
Email: Stefan.Witzel [at]

Last modified: Mon 04 Jan 2021, 12:05