The Schur Multipliers of SL (3, Z) and &L (4, Z).
The structure of subnormal subgroups of symplectic groups over local rings.
The subgroups in the special linear group over a skew field that contain the group of diagonal matrices
The theorem of Borevich for the hyperbolic unitary group over a noncommutative field.
The upper central series of some matrix groups
Theory of coverings in the study of Riemann surfaces
For a G-covering Y → Y/G = X induced by a properly discontinuous action of a group G on a topological space Y, there is a natural action of π(X,x) on the set F of points in Y with nontrivial stabilizers in G. We study the covering of X obtained from the universal covering of X and the left action of π(X,x) on F. We find a formula for the number of fixed points of an element g ∈ G which is a generalization of Macbeath's formula applied to an automorphism of a Riemann surface. We give a new method...
Torsion Free Subgroups of Fuchsian Groups and Tessalations of Surfaces.
Torsion matrices over commutative integral group rings.
Let ZA be the integral group ring of a finite abelian group A, and n a positive integer greater than 5. We provide conditions on n and A under which every torsion matrix U, with identity augmentation, in GLn(ZA) is conjugate in GLn(QA) to a diagonal matrix with group elements on the diagonal. When A is infinite, we show that under similar conditions, U has a group trace and is stably conjugate to such a diagonal matrix.
Traces, lengths, axes and commensurability
The focus of this paper are questions related to how various geometric and analytical properties of hyperbolic 3-manifolds determine the commensurability class of such manifolds. The paper is for the large part a survey of recent work.
Tresses, monodromie et le groupe symplectique.
Triangle subgroups of Kleinian groups.
Two Generator Fuchsian Groups of Genus One.
Two-Generator Discrete Free Products.
Über die Erzeugbarkeit paramodularer Gruppen durch Elemente mit Fixpunkten.
Über die Heckeschen Gruppen G(...) II.
Über die Konstruktion zykloider Kongruenzgruppen in der rationalen Modulgruppe.
Über eine Klasse von arithmetischen definierbaren Normalteilern der Modulgruppe.
Über Erzeugende ebener diskontinuierlicher Gruppen.
Über explizite Präsentationen Hilbertscher Modulgruppen zu totalrellen Körpern der Klassenzahlen eins.
Über Homomorphismen einer Gruppe von Matrizen