Automorphismen und Erzeugende für Gruppen mit einer definierenden Relation.
Automorphisms of linear semigroups over division rings.
Automorphisms of Verardi groups: small upper triangular matrices over rings.
Beiträge zur geometrischen Interpretation binärer Formen
Beweis des Satzes, dass diejenigen endlichen linearen Substitutionsgruppen, in welchen einige durchgehends verschwindende Coefficienten auftreten, intransitiv sind
Big groups of automorphisms of some Klein surfaces.
Sea Xp una superficie de Klein compacta con borde de gen algebraico p ≥ 2. Se sabe que si G es un grupo de automorfismos de Xp entonces |G| ≤ 12(p- 1). Se dice que G es un grupo grande de gen p si |G| > 4(p -1). En el presente artículo se halla una familia de enteros p para los que el único grupo grande de gen p son los grupos diédricos. Esto significa que, en términos del gen real introducido por C. L. May, para tales valores de p no existen grupos grandes de gen real p.
Bounds for quaternionic line systems and reflection groups.
Calculating canonical distinguished involutions in the affine Weyl groups.
Character theory of symmetric groups, analysis of long relators, and random walks.
Chromatic Plane Compositions
Classical projective geometry and arithmetic groups.
Clifford k-algebras and k*-groups.
Clusters in middle-phase percolation on hyperbolic plane
I consider p-Bernoulli bond percolation on transitive, nonamenable, planar graphs with one end and on their duals. It is known from [BS01] that in such a graph G we have three essential phases of percolation, i.e. , where is the critical probability and -the unification probability. I prove that in the middle phase a.s. all the ends of all the infinite clusters have one-point boundaries in ∂ℍ². This result is similar to some results in [Lal].
Coarse structures and group actions
The main results of the paper are: Proposition 0.1. A group G acting coarsely on a coarse space (X,𝓒) induces a coarse equivalence g ↦ g·x₀ from G to X for any x₀ ∈ X. Theorem 0.2. Two coarse structures 𝓒₁ and 𝓒₂ on the same set X are equivalent if the following conditions are satisfied: (1) Bounded sets in 𝓒₁ are identical with bounded sets in 𝓒₂. (2) There is a coarse action ϕ₁ of a group G₁ on (X,𝓒₁) and a coarse action ϕ₂ of a...
Cofinitary and Contrafinitary Linear Groups.
Cohomologie des groupes discontinus
Cohomology of arithmetic subgroups of SL3 at infinity.
Cohomology of Congruence Subgroups of SL (n,Z).
Collineation groups of translation planes of small dimension.
Commutator subgroups of the extended Hecke groups
Hecke groups are the discrete subgroups of generated by and . The commutator subgroup of (, denoted by , is studied in [2]. It was shown that is a free group of rank . Here the extended Hecke groups , obtained by adjoining to the generators of , are considered. The commutator subgroup of is shown to be a free product of two finite cyclic groups. Also it is interesting to note that while in the case, the index of is changed by , in the case of , this number is either 4 for...