On the Zassenhaus Conjecture and the subgroups of finite index of the group of units of integral group rings. Vrije Universiteit Brussel
Discontinuous group actions in hyperbolic geometry with application to units in group rings Vrije Universiteit Brussel
Groups, group rings, braces and set-theoretic solutions of the Yang-Baxter Equation Vrije Universiteit Brussel
Rank one groups over local rings Ghent University
We characterize the class of linear algebraic groups over local rings via an action on an infinite tree. We generalize the theory of Moufang sets to an axiomatic theory determining those groups. Moreover, we study the normal subgroups of those groups. Each ideal of a local ring gives rise to such a normal subgroup, and the question is whether every normal subgroup arises in this fashion.