We study the twisted index theory of elliptic operators on orbifold covering spaces of compact good orbifolds, which are invariant under a projective action of the orbifold fundamental group. We apply these results to obtain qualitative results on real and complex hyperbolic spaces in 2 and 4 dimensions, related to generalizations of the Bethe-Sommerfeld conjecture and the Ten Martini Problem, ...

Let G be a group hyperbolic relative to a finite collection of subgroups P. Let F be the family of subgroups consisting of all the conjugates of subgroups in P, all their subgroups, and all finite subgroups. Then there is a cocompact model for EFG. This result was known in the torsion-free case. In the presence of torsion, a new approach was necessary. Our method is to exploit the notion of dis...

We prove that any complete hyperbolic 3–manifold with finitely generated fundamental group, with a single topological end, and which embeds into S is the geometric limit of a sequence of hyperbolic knot complements in S. In particular, we derive the existence of hyperbolic knot complements which contain balls of arbitrarily large radius. We also show that a complete hyperbolic 3–manifold with t...

The notion of a hyperbolic group was introduced by Gromov [Gr]. Associated to any hyperbolic group, Γ, is its boundary, ∂Γ. This is a metrisable compactum on which Γ acts by homeomorphism. If Γ is non-elementary (i.e. not finite or virtually cyclic), then ∂Γ is perfect. The induced action of Γ on the space of distinct triples of ∂Γ is properly discontinuous and cocompact. The main result of thi...

In the present paper, the concepts of module (uniform) approximate amenability and contractibility of Banach algebras that are modules over another Banach algebra, are introduced. The general theory is developed and some hereditary properties are given. In analogy with the Banach algebraic approximate amenability, it is shown that module approximate amenability and contractibility are the same ...

‎we say that a module $m$ is a emph{cms-module} if‎, ‎for every cofinite submodule $n$ of $m$‎, ‎there exist submodules $k$ and $k^{'}$ of $m$ such that $k$ is a supplement of $n$‎, ‎and $k$‎, ‎$k^{'}$ are mutual supplements in $m$‎. ‎in this article‎, ‎the various properties of cms-modules are given as a generalization of $oplus$-cofinitely supplemented modules‎. ‎in particular‎, ‎we prove tha...

We prove a formula for the speed of distance stationary random sequences generalizing law large numbers Karlsson and Ledrappier. A particular case is classical largest Lyapunov exponent i.i.d. matrix products, but our result has applications in various different contexts. In many situations it gives method to estimate speed, others allows obtain results dimension drop escape measures related wa...

In this paper, we define super Hilbert module and investigate frames in this space. Super Hilbert modules are  generalization of super Hilbert spaces in Hilbert C*-module setting. Also, we define frames in a super Hilbert module and characterize them by using of the concept of g-frames in a Hilbert C*-module. Finally, disjoint frames in Hilbert C*-modules are introduced and investigated.

Let \(1 \to K G\,\mathop \limits^\pi \,Q\) be an exact sequence of hyperbolic groups. Q1 < Q a quasiconvex subgroup and let G1 = ??1(Q1). Under relatively mild conditions (e.g. if is closed surface group or free convex cocompact), we show that infinite index subgroups are in G. Related results proven for metric bundles, developable complexes groups graphs