2 Rigidity of non-uniform rank one lattices 6 2.1 Theorems of Richard Schwartz . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.2 Finite volume real hyperbolic manifolds . . . . . . . . . . . . . . . . . . . . . . . 8 2.3 Proof of Theorem 2.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.4 Proof of Theorem 2.1 . . . . . . . . . . . . . . . . . . . . . . . . ...

Building upon work of Y. Shalom we give a homological-algebra flavored definition of an induction map in group homology associated to a topological coupling. As an application we obtain that the cohomological dimension cdR over a commutative ring R satisfies the inequality cdR(Λ) ≤ cdR(Γ) if Λ embeds uniformly into Γ and cdR(Λ) < ∞ holds. Another consequence of our results is that the Hirsch ra...

1 2 3 Let T be a rooted tree and Iso(T ) be the group of its isometries. We study closed subgroups G of Iso(T ) with respect to the number of conjugacy classes of Iso(T ) having representatives in G.

We investigate the quasi-isometry classification of the right-angled Coxeter groups WΓ which are 1-ended and have triangle-free defining graph Γ. We begin by characterising those WΓ which split over 2-ended subgroups, and those which are cocompact Fuchsian, in terms of properties of Γ. This allows us to apply a theorem of Papasoglu [21] to distinguish several quasi-isometry classes. We then car...