Module

NormalizationPrimeInertia.lean

Nyll.EtaleFundamentalGroups.StrictHenselian.NormalizationPrimeInertia
5 declarations indexed from sourceView source ↗

Original normalization inertia on the literal prime localization

Use the already fixed integral-closure Galois action and its existing scalar commutation owner. An element of the original ideal inertia therefore gives the individual native localization automorphism, with the literal base and residue squares. No alternate action on the localization is installed. These are the actual inputs for the separately proved stalk rigidity result.

Declarations

EtaleFundamentalGroups.StrictHenselian.normalizationCoefficientMap
Source context 5 commands

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

noncomputable section
namespace EtaleFundamentalGroups.StrictHenselian
open EtaleFundamentalGroups.Inertia
universe u v w
attribute [local instance] normalizationInertiaImageAction normalizationInertiaCoefficientCommClass
def normalizationCoefficientMap
    (A : Type u) (L : Type w) [CommRing A] [Field L] [Algebra A L] :
    A →+* integralClosure A L
EtaleFundamentalGroups.StrictHenselian.normalizationCoefficientMap_commutes
Source context 6 commands

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

noncomputable section
namespace EtaleFundamentalGroups.StrictHenselian
open EtaleFundamentalGroups.Inertia
universe u v w
attribute [local instance] normalizationInertiaImageAction normalizationInertiaCoefficientCommClass
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing A] [Field K] [Field L]
  [Algebra A K] [IsFractionRing A K] [Algebra K L] [Algebra A L]
  [IsScalarTower A K L] [IsGalois K L]
theorem normalizationCoefficientMap_commutes (σ : Gal(L/K)) :
    (MulSemiringAction.toRingEquiv Gal(L/K) (integralClosure A L) σ).toRingHom.comp
        (normalizationCoefficientMap A L) = normalizationCoefficientMap A L
EtaleFundamentalGroups.StrictHenselian.normalizationPrimeInertiaRingEquiv

An element of the original normalization-prime inertia acts on the literal localization, through the existing canonical normalization action.

Source context 6 commands

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

noncomputable section
namespace EtaleFundamentalGroups.StrictHenselian
open EtaleFundamentalGroups.Inertia
universe u v w
attribute [local instance] normalizationInertiaImageAction normalizationInertiaCoefficientCommClass
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing A] [Field K] [Field L]
  [Algebra A K] [IsFractionRing A K] [Algebra K L] [Algebra A L]
  [IsScalarTower A K L] [IsGalois K L]
def normalizationPrimeInertiaRingEquiv
    (Q : Ideal (integralClosure A L)) [Q.IsPrime]
    (σ : Gal(L/K)) (hσ : σ ∈ Q.inertia Gal(L/K)) :
    Localization.AtPrime Q ≃+* Localization.AtPrime Q
EtaleFundamentalGroups.StrictHenselian.normalizationPrimeInertiaRingEquiv_comp_baseMap

The original normalization inertia preserves the literal composite from the base into the prime localization.

Source context 6 commands

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

noncomputable section
namespace EtaleFundamentalGroups.StrictHenselian
open EtaleFundamentalGroups.Inertia
universe u v w
attribute [local instance] normalizationInertiaImageAction normalizationInertiaCoefficientCommClass
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing A] [Field K] [Field L]
  [Algebra A K] [IsFractionRing A K] [Algebra K L] [Algebra A L]
  [IsScalarTower A K L] [IsGalois K L]
theorem normalizationPrimeInertiaRingEquiv_comp_baseMap
    (Q : Ideal (integralClosure A L)) [Q.IsPrime]
    (σ : Gal(L/K)) (hσ : σ ∈ Q.inertia Gal(L/K)) :
    (normalizationPrimeInertiaRingEquiv A K L Q σ hσ).toRingHom.comp
        (integralClosurePrimeBaseMap A L Q) = integralClosurePrimeBaseMap A L Q
EtaleFundamentalGroups.StrictHenselian.normalizationPrimeInertiaRingEquiv_comp_residue

The original normalization inertia acts trivially on the actual residue field of the literal prime localization.

Source context 6 commands

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

noncomputable section
namespace EtaleFundamentalGroups.StrictHenselian
open EtaleFundamentalGroups.Inertia
universe u v w
attribute [local instance] normalizationInertiaImageAction normalizationInertiaCoefficientCommClass
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing A] [Field K] [Field L]
  [Algebra A K] [IsFractionRing A K] [Algebra K L] [Algebra A L]
  [IsScalarTower A K L] [IsGalois K L]
theorem normalizationPrimeInertiaRingEquiv_comp_residue
    (Q : Ideal (integralClosure A L)) [Q.IsPrime]
    (σ : Gal(L/K)) (hσ : σ ∈ Q.inertia Gal(L/K)) :
    (IsLocalRing.residue (Localization.AtPrime Q)).comp
        (normalizationPrimeInertiaRingEquiv A K L Q σ hσ).toRingHom =
      IsLocalRing.residue (Localization.AtPrime Q)