Profinite invariants of arithmetic groups
Group Theory
2019-01-23 v2
Abstract
We prove that the sign of the Euler characteristic of arithmetic groups with CSP is determined by the profinite completion. In contrast, we construct examples showing that this is not true for the Euler characteristic itself and that the sign of the Euler characteristic is not profinite among general residually finite groups of type . Our methods imply similar results for -torsion as well as a strong profiniteness statement for Novikov-Shubin invariants.
Cite
@article{arxiv.1901.01227,
title = {Profinite invariants of arithmetic groups},
author = {Holger Kammeyer and Steffen Kionke and Jean Raimbault and Roman Sauer},
journal= {arXiv preprint arXiv:1901.01227},
year = {2019}
}
Comments
small changes in introduction and proof of prop 2.7