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Now showing items 11-16 of 16
The integral homology of PSL(2) of imaginary quadratic integers with nontrivial class group
(2011)
We show that a cellular complex defined by Flöge allows us to determine the integral homology of the Bianchi groups PSL(2)(O[-m]), where O[-m] is the ring of integers of an imaginary quadratic number field Q [square root ...
On Level One Cuspidal Bianchi Modular Forms
(2013)
In this paper, we present the outcome of vast computer calculations, locating several of the very rare instances of level one cuspidal Bianchi modular forms that are not lifts of elliptic modular forms.
On a question of Serre
(2012)
Consider an imaginary quadratic number field Q(root -m), with m a square-free positive integer, and its ring of integers {O} . The Bianchi groups are the groups SL2{O}. Further consider the Borel-Serre compactification [7] ...
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 ...
The mod 2 cohomology rings of SL2 of the imaginary quadratic integers
(Elsevier ScienceDirect, 2015-09-28)
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, ...
Complexifiable characteristic classes
(Springer, 2014-01)
We examine the topological characteristic cohomology classes of complexified vector bundles. In particular, all the classes coming from the real vector bundles underlying the complexification are determined.