When is Group Cohomology Finitary?
Abstract
If is a group, then we say that the functor is finitary if it commutes with all filtered colimit systems of coefficient modules. We investigate groups with cohomology almost everywhere finitary; that is, groups with th cohomology functors finitary for all sufficiently large . We establish sufficient conditions for a group possessing a finite dimensional model for to have cohomology almost everywhere finitary. We also prove a stronger result for the subclass of groups of finite virtual cohomological dimension, and use this to answer a question of Leary and Nucinkis. Finally, we show that if is a locally (polycyclic-by-finite) group, then has cohomology almost everywhere finitary if and only if has finite virtual cohomological dimension and the normalizer of every non-trivial finite subgroup of is finitely generated.
Cite
@article{arxiv.0803.2540,
title = {When is Group Cohomology Finitary?},
author = {Martin Hamilton},
journal= {arXiv preprint arXiv:0803.2540},
year = {2008}
}
Comments
26 pages