absolute Galois group
Let be a field. Let denote the separable closure of . Then the Galois group of the extension is called absolute Galois group of .
We have is equivalent to the fundamental group of the scheme .
An instance of Grothendieck's Galois theory is the following:
from the category of étale schemes to the category of sets equipped with an action of the absolute Galois group is an equivalence of categories.
Revised on September 12, 2012 20:36:34
by Tim Porter