Homepage of Benjamin Brück

I am a PhD student in mathematics at Universität Bielefeld and my advisor is Kai-Uwe Bux. I did my Bachelor and Master studies at WWU Münster and wrote my Master thesis during a one-semester stay at Université Claude Bernard Lyon 1 under the supervision of Katrin Tent, Rizos Sklinos and Tuna Altınel.
Currently, I am visiting Mladen Bestvina at the University of Utah.

Contact information

If you want to know how to reach me, click here.
Here you can find the homepage of our working group.

Research interests

Geometric Group Theory; Topology; Model Theory; RAAGs and their automorphism groups, in particular free groups; Coxeter groups; Buildings

Publications

Recent and upcoming talks

tba - Max Dehn Seminar, Salt Lake City, 30th of October 2019;

"Between Tits buildings and free factor complexes" - Southampton-Bielefeld Geometric Group Theory Meeting, Southampton, September 2019;

"Between Tits buildings and free factor complexes" - Algebra/Topology Seminar, Copenhagen, September, 2019;

"Parabolic subgroups and spherical complexes for Out(RAAGs)" - Oberseminar Modelltheorie, Geometrie und Gruppentheorie, Münster, June 2019;

"Topology of free factor complexes" - AG-Seminar Topologie, Karlsruhe, June 2019;

"Coset complexes and the Cohen-Macaulay property" - Oberseminar Algebra und Geometrie, Magdeburg, April 2019;

"Topology of free factor complexes" - SPP 2026 - Geometry at infinity conference, Münster, April 2019; Slides of this talk

"Reflections and harmonies: Coxeter groups in music theory" - SYMBol, Bielefeld, February 2019

"Free factors at infinity" - Bielefeld-Münster Seminar on Groups, Geometry and Topology, January 2019

"Finding fibres for free factors" - Junior Topology and Group Theory Seminar, Oxford, October 2018

"Higher connectivity of free factor complexes" - Poster presented at Geometric Group Theory in Campinas, July 2018

"Buildings and the free factor complex" - Junior Geometry and Topology Seminar (GATEWAY), Warwick, April 2018

"Out(Fn) and Outer Space" - BKMR Research Seminar on Geometric Group Theory, Münster, August 2017

"Higher generating subgroups in Aut(Fn) and GLn(ℤ)" - Bielefeld-Münster Seminar on Groups, Geometry and Topology, July 2017

"Bases in non-standard models of the theory of free groups" - Oberseminar Gruppen und Geometrie, Bielefeld, June 2016

"Weight in non-standard models of the theory of free groups" - Oberseminar Modelltheorie, Geometrie und Gruppentheorie, Münster, May 2016

"Weight in non-standard models of the theory of free groups" - Models and Groups 6, Istanbul, March 2016

Longer research stays

In October and November 2019, I am visiting Mladen Bestvina at the University of Utah.

In October and November 2018, I visited Ric Wade at the University of Oxford.

Organisation

I am organising a weekly meeting on geometric group theory in Bielefeld: Friday GGT.

I was one of the organisers of the conference Outer Space in Bielefeld which took place in Bielefeld from 24th to 26th of September 2019.

I was one of the organisers of the block seminar Arithmetic groups and Rigidity which took place in Bielefeld from 21st to 23rd of March 2018. A shortened pdf-version of the introduction I gave at this seminar can be found here.

Teaching

From 2013 to 2015, I gave tutorials in Münster for the lectures Analysis II, Introduction to Algebra, Quadratic Forms, Higher Algebra I and Stable Groups. In 2016 and 2017, I held tutorials for the lectures Analysis II, Algebra I, Riemannian Geometry and Ordinary differential equations in Bielefeld.
In the winter semester 2017/2018, I was leading the discussion session for the course Groups acting on trees.

Miscellaneous

The following link leads to a petition asking to free Tuna Altınel, who was arrested in Turkey: Free Tuna Altınel. Further information can be found here.

I am a member of the DFG priority programm "Geometry at infinity": SPP 2026.