Groups of simple and multiple antisymmetry of borders.
Groups of simple and multiple antisymmetry of similitude in
Groups of simple and multiple ribbon antisymmetry.
Groups with Domains of Discontinuity.
Growth functions on Fuchsian groups and the Euler characteristic.
Gruppentheoretischer Aufbau affiner Räume einer beliebigen Dimension ... 2 auf der Grundlage von Schrägspiegelungen
Hilbert symbols, class groups and quaternion algebras
Let be a quaternion algebra over a number field . To a pair of Hilbert symbols and for we associate an invariant in a quotient of the narrow ideal class group of . This invariant arises from the study of finite subgroups of maximal arithmetic kleinian groups. It measures the distance between orders and in associated to and If , we compute by means of arithmetic in the field The problem of extending this algorithm to the general case leads to studying a finite graph associated...
Holonomy groups of five dimensional Bieberbach groups.
Holonomy groups of flat manifolds with the property
Let M be a flat manifold. We say that M has the property if the Reidemeister number R(f) is infinite for every homeomorphism f: M → M. We investigate relations between the holonomy representation ρ of M and the property. When the holonomy group of M is solvable we show that if ρ has a unique ℝ-irreducible subrepresentation of odd degree then M has the property. This result is related to Conjecture 4.8 in [K. Dekimpe et al., Topol. Methods Nonlinear Anal. 34 (2009)].
Homomorphisms of constant stretch between Möbius groups.
Homomorphisms of Unitary Groups.
Hyperbolic monodromy groups for the hypergeometric equation and Cartan involutions
We give a criterion which ensures that a group generated by Cartan involutions in the automorph group of a rational quadratic form of signature is “thin”, namely it is of infinite index in the latter. It is based on a graph defined on the integral Cartan root vectors, as well as Vinberg’s theory of hyperbolic reflection groups. The criterion is shown to be robust for showing that many hyperbolic hypergeometric groups for are thin.
Image sampling with quasicrystals.
Independent generators for congruence subgroups of Hecke groups.
Inequalities for Möbius transformations and discrete groups.
Infinite classes of simple and multiple antisymmetry four-dimensional point groups.
Infinite dimensional general linear groups have finite width.
Infinite dimensional linear groups with many G - invariant subspaces
Let F be a field, A be a vector space over F, GL(F, A) be the group of all automorphisms of the vector space A. A subspace B of A is called nearly G-invariant, if dimF(BFG/B) is finite. A subspace B is called almost G-invariant, if dim F(B/Core G(B)) is finite. In the current article, we study linear groups G such that every subspace of A is either nearly G-invariant or almost G-invariant in the case when G is a soluble p-group where p = char F.
Integral quadratic forms : applications to algebraic geometry
Invariants of a class of transformation groups.