A lift from group cohomology to spectra for trivial profinite actions
Abstract
Let be a profinite group, a discrete -spectrum with trivial action, and the continuous homotopy fixed points. For any ("" for open), is a -spectrum with trivial action. We construct a zigzag \text{colim}\,_N \,X^{hG/N} \buildrel\Phi\over\longrightarrow \text{colim}\,_N \,(X^{hN})^{hG/N} \buildrel\Psi\over\longleftarrow X^{hG}, where is a weak equivalence. When is a weak equivalence, this zigzag gives an interesting model for (for example, its Spanier-Whitehead dual is ). We prove that this happens in the following cases: (1) ; (2) is bounded above; (3) there exists cofinal in , such that for each , , for . Given (3), for each , there is a weak equivalence and . For case (3), we give a series of corollaries and examples. As one instance of a family of examples, if is a prime, the th Morava -theory at for some , and the -adic integers, then for each , (3) is satisfied when is closed, , and .
Keywords
Cite
@article{arxiv.1908.01898,
title = {A lift from group cohomology to spectra for trivial profinite actions},
author = {Daniel G. Davis},
journal= {arXiv preprint arXiv:1908.01898},
year = {2019}
}
Comments
18 pages; submitted for publication