Computations of K- and L-Theory of Cocompact Planar Groups

نویسنده

  • WOLFGANG LÜCK
چکیده

The verification of the isomorphism conjectures of Baum and Connes and Farrell and Jones for certain classes of groups is used to compute the algebraic Kand L-theory and the topologicalK-theory of cocompact planar groups (= cocompact N.E.C-groups) and of groupsG appearing in an extension 1 → Zn → G → π → 1 where π is a finite group and the conjugation πaction on Zn is free outside 0 ∈ Zn. These computations apply, for instance, to two-dimensional crystallographic groups and cocompact Fuchsian groups. Mathematics Subject Classifications (2000): 19B28, 19D50, 19G24, 19K99.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Rational Computations of the Topological K-Theory of Classifying Spaces of Discrete Groups

We compute rationally the topological (complex) K-theory of the classifying space BG of a discrete group provided that G has a cocompact G-CW -model for its classifying space for proper G-actions. For instance word-hyperbolic groups and cocompact discrete subgroups of connected Lie groups satisfy this assumption. The answer is given in terms of the group cohomology of G and of the centralizers ...

متن کامل

Equivariant K-homology for Hyperbolic Reflection Groups

We compute the equivariant K-homology of the classifying space for proper actions, for cocompact 3-dimensional hyperbolic reflection groups. This coincides with the topological K-theory of the reduced C∗-algebra associated to the group, via the Baum-Connes conjecture. We show that, for any such reflection group, the associated K-theory groups are torsion-free. This means that we can complete pr...

متن کامل

A convex combinatorial property of compact sets in the plane and its roots in lattice theory

K. Adaricheva and M. Bolat have recently proved that if $,mathcal U_0$ and $,mathcal U_1$ are circles in a triangle with vertices $A_0,A_1,A_2$, then there exist $jin {0,1,2}$ and $kin{0,1}$ such that $,mathcal U_{1-k}$ is included in the convex hull of $,mathcal U_kcup({A_0,A_1, A_2}setminus{A_j})$. One could say disks instead of circles.Here we prove the existence of such a $j$ and $k$ ...

متن کامل

The Lower Algebraic K-theory of Fuchsian Groups

Let Γ be a cocompact Fuchsian group. We calculate the lower algebraic K-theory of the integral group ring ZΓ and find an explicit formula for Ki(ZΓ), i ≤ 1, in terms of the lower K-groups of finite cyclic groups.

متن کامل

Jørgensen Number and Arithmeticity

The Jørgensen number of a rank-two non-elementary Kleinian group Γ is J(Γ) = inf{|trX − 4|+ |tr[X,Y ]− 2| : 〈X,Y 〉 = Γ}. Jørgensen’s Inequality guarantees J(Γ) ≥ 1, and Γ is a Jørgensen group if J(Γ) = 1. This paper shows that the only torsion-free Jørgensen group is the figure-eight knot group, identifies all non-cocompact arithmetic Jørgensen groups, and establishes a characterization of coco...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2000