Galois actions on homotopy groups
Abstract
We study the Galois actions on the l-adic schematic and Artin-Mazur homotopy groups of algebraic varieties. For proper varieties of good reduction over a local field K, we show that the l-adic schematic homotopy groups are mixed representations explicitly determined by the Galois action on cohomology of Weil sheaves, whenever l is not equal to the residue characteristic p of K. For quasi-projective varieties of good reduction, there is a similar characterisation involving the Gysin spectral sequence. When l=p, a slightly weaker result is proved by comparing the crystalline and p-adic schematic homotopy types. Under favourable conditions, a comparison theorem transfers all these descriptions to the Artin-Mazur homotopy groups.
Cite
@article{arxiv.0712.0928,
title = {Galois actions on homotopy groups},
author = {J. P. Pridham},
journal= {arXiv preprint arXiv:0712.0928},
year = {2014}
}
Comments
72 pages; v2 corrections to Section 3; v3 references updated; v4 final version