Torsion homology of arithmetic lattices and K2 of imaginary fields
arXiv:1303.6132 · doi:10.1007/s00209-014-1298-2
Abstract
We study upper bounds for the torsion in homology of nonuniform arithmetic lattices. Together with recent results of Calegari-Venkatesh, this can be used to obtain upper bounds on K2 of the ring of integers of totally imaginary fields.
Version 2 is a major update. Result for S-integers added. This allows to show case d=2 (imaginary quadratic fields) and d=4 in Theorem 1.3, previously excluded. 12 pages (previously 6)