An \'etale realization which does not exist
Abstract
For a global field, local field, or finite field with infinite Galois group, we show that there can not exist a functor from the Morel--Voevodsky -homotopy category of schemes over to a genuine Galois equivariant homotopy category satisfying a list of hypotheses one might expect from a genuine equivariant category and an \'etale realization functor. For example, these hypotheses are satisfied by genuine -spaces and the -realization functor constructed by Morel--Voevodsky. This result does not contradict the existence of \'etale realization functors to (pro-)spaces, (pro-)spectra or complexes of modules with actions of the absolute Galois group when the endomorphisms of the unit is not enriched in a certain sense. It does restrict enrichments to representation rings of Galois groups.
Keywords
Cite
@article{arxiv.1709.09999,
title = {An \'etale realization which does not exist},
author = {Jesse Leo Kass and Kirsten Wickelgren},
journal= {arXiv preprint arXiv:1709.09999},
year = {2018}
}
Comments
18 pages. To appear in the New Directions in Homotopy Theory volume of Contemporary Mathematics. V2 has a slightly generalized main theorem, and stable realization functors are explicitly assumed to be additive, which is necessary. V3 minor modifications