Browsing Mathematics by Subject "Bianchi groups"
Now showing items 16 of 6

Accessing the cohomology of discrete groups above their virtual cohomological dimension
(2014)We introduce a method to explicitly determine the FarrellTate cohomology of discrete groups. We apply this method to the Coxeter triangle and tetrahedral groups as well as to the Bianchi groups, i.e. PSL_2 over the ring ... 
Cell complexes database for the Bianchi groups
(NUI Galway, 20160518)This is a database of quotients by Bianchi groups of twodimensional cellular equivariant retracts of Hyperbolic threespace. The Bianchi groups SL(2, A), with A the ring of integers in the imaginary quadratic number field ... 
The homological torsion of PSL_2 of the imaginary quadratic integers
(2013)The Bianchi groups are the groups (P)SL2 over a ring of integers in an imaginary quadratic number field. We reveal a correspondence between the homological torsion of the Bianchi groups and new geometric invariants, which ... 
Homology and Ktheory of the Bianchi groups
(2011)We reveal a correspondence between the homological torsion of the Bianchi groups and new geometric invariants, which are effectively computable thanks to their action on hyperbolic space. We use it to explicitly compute ... 
The mod 2 cohomology rings of SL2 of the imaginary quadratic integers
(Elsevier ScienceDirect, 20150928)We establish general dimension formulae for the second page of the equivariant spectral sequence of the action of the SL2 groups over imaginary quadratic integers on their associated symmetric space. By way of doing this, ... 
On the equivariant Khomology of PSL_2 of the imaginary quadratic integers
(Association des Annales de l'Institut Fourier, 201609)We establish formulae for the part due to torsion of the equivariant $K$homology of all the Bianchi groups (PSL$_2$ of the imaginary quadratic integers), in terms of elementary numbertheoretic quantities. To achieve this, ...