Module

FieldSourceGaloisPoint.lean

Nyll.EtaleFundamentalGroups.GeometricFiber.FieldSourceGaloisPoint
1 declaration indexed from sourceView source ↗

The actual point action of the supplied Galois comparison

This computation is proved over abstract fields, so callers retain their original field structures without unfolding the construction of the fiber automorphism group at those concrete fields.

Declarations

AlgebraicGeometry.FiniteEtale.suppliedGaloisEquivFundamentalGroup_point

The supplied Galois automorphism acts by its literal spectrum map.

Source context 5 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
open CategoryTheory
namespace AlgebraicGeometry.FiniteEtale
universe u
variable (F Ω : Type u) [Field F] [Field Ω] [Algebra F Ω]
  [IsSepClosure F Ω] [IsSepClosed Ω]
theorem suppliedGaloisEquivFundamentalGroup_point
    (σ : Gal(Ω/F)) (X : FiniteEtale (Spec (.of F))) (x : (fib F Ω).obj X) :
    (fiberObjEquivHom (ξ F Ω) X
      ((suppliedGaloisEquivFundamentalGroup F Ω σ).hom.app X x)).left =
      Spec.map (CommRingCat.ofHom σ.toRingHom) ≫
        (fiberObjEquivHom (ξ F Ω) X x).left