3 papers
math.GR2026
Lattices determined by their commensurator
Adrien Le Boudec, Colin Reid
Let be a finitely generated cocompact lattice of a totally disconnected locally compact group , and a dense subgroup of that contains and commensurates . We stu…
math.GR2025
Rigidity and flexibility results for groups with a common cocompact envelope
Adrien Le Boudec
A locally compact group is a cocompact envelope of a group if contains a copy of as a discrete and cocompact subgroup. We study the problem that takes two finitel…
math.GR2025
On commensurators of free groups and free pro-p groups
Yiftach Barnea, Mikhail Ershov, Adrien Le Boudec +3
We study the commensurators of free groups and free pro- groups, as well as certain subgroups of these. We prove that the commensurator of a non-abelian free group of…