Module

NormalizationPrimeField.lean

Nyll.EtaleFundamentalGroups.StrictHenselian.NormalizationPrimeField
13 declarations indexed from sourceView source ↗

The actual normalization-prime localization in the ambient Galois field

The shared integral-closure fraction supplier and the existing canonical prime-localization lift construct the literal map into the original field. The native coefficient equations prove injectivity, its base square, and compatibility with each original inertia element. All scalar actions are those of the existing owners; no action on the localization is introduced.

Declarations

EtaleFundamentalGroups.StrictHenselian.primeLocalizationFieldMap
Source context 4 commands

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

noncomputable section
namespace EtaleFundamentalGroups.StrictHenselian
open EtaleFundamentalGroups.Inertia
universe u v w
def primeLocalizationFieldMap
    (B : Type u) (F : Type v) [CommRing B] [IsDomain B]
    [Field F] [Algebra B F] [IsFractionRing B F]
    (Q : Ideal B) [Q.IsPrime] : Localization.AtPrime Q →+* F
EtaleFundamentalGroups.StrictHenselian.primeLocalizationFieldMap_comp
Source context 4 commands

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

noncomputable section
namespace EtaleFundamentalGroups.StrictHenselian
open EtaleFundamentalGroups.Inertia
universe u v w
theorem primeLocalizationFieldMap_comp
    (B : Type u) (F : Type v) [CommRing B] [IsDomain B]
    [Field F] [Algebra B F] [IsFractionRing B F]
    (Q : Ideal B) [Q.IsPrime] :
    (primeLocalizationFieldMap B F Q).comp (algebraMap B (Localization.AtPrime Q)) =
      algebraMap B F
EtaleFundamentalGroups.StrictHenselian.primeLocalizationFieldMap_injective
Source context 4 commands

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

noncomputable section
namespace EtaleFundamentalGroups.StrictHenselian
open EtaleFundamentalGroups.Inertia
universe u v w
theorem primeLocalizationFieldMap_injective
    (B : Type u) (F : Type v) [CommRing B] [IsDomain B]
    [Field F] [Algebra B F] [IsFractionRing B F]
    (Q : Ideal B) [Q.IsPrime] :
    Function.Injective (primeLocalizationFieldMap B F Q)
EtaleFundamentalGroups.StrictHenselian.integralClosure_subtype_comp
Source context 4 commands

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

noncomputable section
namespace EtaleFundamentalGroups.StrictHenselian
open EtaleFundamentalGroups.Inertia
universe u v w
theorem integralClosure_subtype_comp
    (A : Type u) (L : Type v) [CommRing A] [Field L] [Algebra A L] :
    (integralClosure A L).toSubring.subtype.comp (algebraMap A (integralClosure A L)) =
      algebraMap A L
EtaleFundamentalGroups.StrictHenselian.actionInertiaLocalizationRingHom
Source context 4 commands

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

noncomputable section
namespace EtaleFundamentalGroups.StrictHenselian
open EtaleFundamentalGroups.Inertia
universe u v w
def actionInertiaLocalizationRingHom
    (G : Type u) (B : Type v) [Group G] [CommRing B] [MulSemiringAction G B]
    (Q : Ideal B) [Q.IsPrime] (σ : G) (hσ : σ ∈ Q.inertia G) :
    Localization.AtPrime Q →+* Localization.AtPrime Q
EtaleFundamentalGroups.StrictHenselian.actionInertiaLocalizationRingHom_comp
Source context 4 commands

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

noncomputable section
namespace EtaleFundamentalGroups.StrictHenselian
open EtaleFundamentalGroups.Inertia
universe u v w
theorem actionInertiaLocalizationRingHom_comp
    (G : Type u) (B : Type v) [Group G] [CommRing B] [MulSemiringAction G B]
    (Q : Ideal B) [Q.IsPrime] (σ : G) (hσ : σ ∈ Q.inertia G) :
    (actionInertiaLocalizationRingHom G B Q σ hσ).comp
        (algebraMap B (Localization.AtPrime Q)) =
      (algebraMap B (Localization.AtPrime Q)).comp (MulSemiringAction.toRingHom G B σ)
EtaleFundamentalGroups.StrictHenselian.primeLocalization_comp_eq_of_coefficients
Source context 4 commands

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

noncomputable section
namespace EtaleFundamentalGroups.StrictHenselian
open EtaleFundamentalGroups.Inertia
universe u v w
theorem primeLocalization_comp_eq_of_coefficients
    (B : Type u) (F : Type v) [CommRing B] [CommRing F]
    (Q : Ideal B) [Q.IsPrime]
    (i : B →+* F) (j : Localization.AtPrime Q →+* F)
    (τ : F →+* F) (s : B →+* B)
    (e : Localization.AtPrime Q →+* Localization.AtPrime Q)
    (hj : j.comp (algebraMap B (Localization.AtPrime Q)) = i)
    (he : e.comp (algebraMap B (Localization.AtPrime Q)) =
      (algebraMap B (Localization.AtPrime Q)).comp s)
    (hτ : τ.comp i = i.comp s) :
    τ.comp j = j.comp e
EtaleFundamentalGroups.StrictHenselian.integralClosurePrimeToAmbientField

The prescribed prime-localization map into the original ambient field. Its fraction-field input is supplied by the actual algebraic normalization.

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
section Algebraic
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing A] [IsDomain A] [Field K] [Field L]
  [Algebra A K] [IsFractionRing A K] [Algebra K L] [Algebra A L]
  [IsScalarTower A K L] [Algebra.IsAlgebraic K L]
def integralClosurePrimeToAmbientField
    (Q : Ideal (integralClosure A L)) [Q.IsPrime] : Localization.AtPrime Q →+* L
EtaleFundamentalGroups.StrictHenselian.integralClosurePrimeToAmbientField_comp_coefficient

The ambient map extends the literal integral-closure inclusion.

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
section Algebraic
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing A] [IsDomain A] [Field K] [Field L]
  [Algebra A K] [IsFractionRing A K] [Algebra K L] [Algebra A L]
  [IsScalarTower A K L] [Algebra.IsAlgebraic K L]
theorem integralClosurePrimeToAmbientField_comp_coefficient
    (Q : Ideal (integralClosure A L)) [Q.IsPrime] :
    (integralClosurePrimeToAmbientField A K L Q).comp
        (algebraMap (integralClosure A L) (Localization.AtPrime Q)) =
      (integralClosure A L).toSubring.subtype
EtaleFundamentalGroups.StrictHenselian.integralClosurePrimeToAmbientField_injective

The literal normalization-prime map into the ambient field is injective.

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
section Algebraic
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing A] [IsDomain A] [Field K] [Field L]
  [Algebra A K] [IsFractionRing A K] [Algebra K L] [Algebra A L]
  [IsScalarTower A K L] [Algebra.IsAlgebraic K L]
theorem integralClosurePrimeToAmbientField_injective
    (Q : Ideal (integralClosure A L)) [Q.IsPrime] :
    Function.Injective (integralClosurePrimeToAmbientField A K L Q)
EtaleFundamentalGroups.StrictHenselian.integralClosurePrimeToAmbientField_comp_baseMap

The original base map is preserved by the actual ambient-field map.

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
section Algebraic
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing A] [IsDomain A] [Field K] [Field L]
  [Algebra A K] [IsFractionRing A K] [Algebra K L] [Algebra A L]
  [IsScalarTower A K L] [Algebra.IsAlgebraic K L]
theorem integralClosurePrimeToAmbientField_comp_baseMap
    (Q : Ideal (integralClosure A L)) [Q.IsPrime] :
    (integralClosurePrimeToAmbientField A K L Q).comp (integralClosurePrimeBaseMap A L Q) =
      algebraMap A L
EtaleFundamentalGroups.StrictHenselian.normalizationInertia_comp_coefficient
Source context 8 commands

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

noncomputable section
namespace EtaleFundamentalGroups.StrictHenselian
open EtaleFundamentalGroups.Inertia
universe u v w
section Galois
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing A] [IsDomain A] [Field K] [Field L]
  [Algebra A K] [IsFractionRing A K] [Algebra K L] [Algebra A L]
  [IsScalarTower A K L] [IsGalois K L]
attribute [local instance] normalizationInertiaImageAction
omit [IsDomain A] in
theorem normalizationInertia_comp_coefficient
    (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
        (algebraMap (integralClosure A L) (Localization.AtPrime Q)) =
      (algebraMap (integralClosure A L) (Localization.AtPrime Q)).comp
        (MulSemiringAction.toRingHom Gal(L/K) (integralClosure A L) σ)
EtaleFundamentalGroups.StrictHenselian.integralClosurePrimeToAmbientField_comp_inertia

The actual inclusion into the ambient field intertwines each original inertia element with its native automorphism of the literal prime localization.

Source context 7 commands

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

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