The limit set intersection theorem for finitely generated Kleinian groups

The limit set intersection theorem for finitely generated Kleinian groups

The proof of the Theorem proceeds by showing that it holds in some special cases involving Kleinian groups with connected limit sets, and then extending to the general case by using a decomposition argument based on the Klein-Maskit combination theorems and a careful tracking of the limit points resulting from this decomposition. We discuss various well-behaved classes of limit points in Sectio...

The Structure Theorem for Finitely Generated Abelian Groups

This paper provides a thorough explication of the Structure Theorem for Abelian groups and of the background information necessary to prove it. The outline of this paper is as follows. We first consider some theorems related to abelian groups and to R-modules. In this section we see that every finitely generated abelian group is the epimorphic image of a finitely generated free abelian group. H...

A Krengel-type theorem for finitely generated nilpotent groups

has density one in Z with respect to some sequence of intervals Ik = [ak, bk] with bk−ak → ∞. (This means that d{Ik}(S) = lim k→∞ |S∩Ik| bk−ak+1 = 1.) A vector f ∈ H is called weakly wandering if there is an infinite set S ⊆ Z such that for any n,m ∈ S, n 6= m, one has 〈Uf, Uf〉 = 0. The following theorem due to U. Krengel gives a characterization of weak mixing in terms of weakly wandering vect...

Finitely Generated Abelian Groups

Finitely Generated Semiautomatic Groups

The present work shows that Cayley automatic groups are semiautomatic and exhibits some further constructions of semiautomatic groups and in particular shows that every finitely generated group of nilpotency class 3 is semiautomatic.