4 papers · 1 filter
Combinatorial Characterizations of Virtually Torsion-Free and Virtually Free Groups
R. Köhl, M. Reza Salarian
We establish combinatorial characterizations of virtually torsion-free and virtually free groups using the canonical graph decomposition theory in \cite{DJKK22}. Our main results s…
Kac-Moody Symmetric Spaces: arbitrary symmetrizable complex or almost split real type
Ralf Köhl, Christian Vock
Kac-Moody symmetric spaces have been introduced by Freyn, Hartnick, Horn and the first-named author for centered Kac-Moody groups, that is, Kac-Moody groups that are generated by t…
The Siegel Modular Group is the Lattice of Minimal Covolume in the Symplectic Group
Amir DžambiÄ, Kristian Holm, Ralf Köhl
Let . We prove that, up to conjugation, is the unique lattice in of the smallest covolume.
Profiniteness of higher rank volume
Holger Kammeyer, Steffen Kionke, Ralf Köhl
We show that the covolume of an irreducible lattice in a higher rank semisimple Lie group with the congruence subgroup property is determined by the profinite completion. Without r…