Videos

Homotopy theory and arithmetic geometry

Presenter
January 24, 2014
Keywords:
  • etale cohomology
  • etale homotopy groups
  • points over schemes
  • Artin-Mazur theory
  • Galois theory
  • profinite completions
MSC:
  • 19F27
  • 19Fxx
  • 13B40
  • 13B35
  • 13B05
  • 13B02
  • 13Bxx
  • 14-xx
Abstract
The solutions in \mathbb{C} to a system of polynomial equations form a nice topological space which is useful even for studying solutions to the polynomials over smaller fields such as R or even Q. To study solutions over Q or characteristic p fields, it is more useful to replace the notion of topological space with an object in a suitable category where one can do homotopy theory, such as the Morel-Voevodsky category for A^1 homotopy theory, and pro-spaces, where one has the étale homotopy type of a scheme. We will define A^1 homotopy theory, étale topological type, and an étale realization between them of Isaksen. We will use this to discuss Grothendieck's anabelian conjectures and obstructions to solutions to polynomial equations.
Supplementary Materials