Module

ArithmeticNormal.lean

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

Arithmetic Normal

The geometric fundamental group has normal image after extension to a separable closure with connected base change.

Declarations

AlgebraicGeometry.FiniteEtale.fundamentalGroupHom_constantField_range_normal

The geometric fundamental group has normal image after extension to a separable closure with connected base change.

Source context 4 commands

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

noncomputable section
open CategoryTheory Limits CategoryTheory.PreGaloisCategory
universe u
namespace AlgebraicGeometry.FiniteEtale
theorem fundamentalGroupHom_constantField_range_normal
    (k L : Type u) [Field k] [Field L] [Algebra k L]
    [Algebra.IsSeparable k L] [IsSepClosed L]
    {X : Scheme.{u}} [CompactSpace X] [QuasiSeparatedSpace X]
    (f : X ⟶ Spec (.of k))
    [ConnectedSpace ↑(Limits.pullback (Spec.map (CommRingCat.ofHom (algebraMap k L))) f)]
    {Ω : Type u} [Field Ω] [IsSepClosed Ω]
    (xi : Spec (.of Ω) ⟶ Limits.pullback (Spec.map (CommRingCat.ofHom (algebraMap k L))) f) :
    (fundamentalGroupHom (Limits.pullback.snd _ f) xi).toMonoidHom.range.Normal