Module

ResidueZeroUnramifiedFaithfulness.lean

Nyll.Yamaguchi26AbfaithfulGalois.Kummer.Concrete.ResidueZeroUnramifiedFaithfulness
2 declarations indexed from sourceView source ↗

Detection through the actual residue Galois quotient

Residue ab-faithfulness detects quotient conjugation on every open normal subgroup that contains the actual inertia kernel.

Declarations

Yamaguchi26AbfaithfulGalois.henselian_openNormal_faithful_of_inertia_le

An open normal subgroup containing the inertia kernel has faithful quotient conjugation whenever the actual residue Galois group is ab-faithful.

Source context 5 commands

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

namespace Yamaguchi26AbfaithfulGalois
open IsLocalRing KummerTheory ValuationTheory.DiscreteValuationField
open ProCGroups.Abelian ProCGroups.FiniteStepSolvableQuotients
open RamificationTheory.HilbertRamification.ValuationSubring
universe u v w x
theorem henselian_openNormal_faithful_of_inertia_le
    {K : Type u} {Ω : Type v} [Field K] [Field Ω] [Algebra K Ω] [IsGalois K Ω]
    (D : HenselianDVF.{u, w} K)
    {Γ : Type x} [LinearOrderedCommGroupWithZero Γ]
    (vΩ : _root_.Valuation Ω Γ) [D.valuation.HasExtension vΩ]
    (hres : IsAbFaithful Gal(ResidueField vΩ.valuationSubring/D.residueField))
    (N : OpenNormalSubgroup Gal(Ω/K))
    (hI : (henselianResidueAction D.valuation vΩ).ker ≤ (N : Subgroup Gal(Ω/K))) :
    Function.Injective (quotientConjugationTopologicalAbelianizationMap
      (N : Subgroup Gal(Ω/K)))
Yamaguchi26AbfaithfulGalois.residueZero_openNormal_faithful_of_inertia_le

Residue ab-faithfulness on its standard algebraic closure gives the same unramified quotient detection for any algebraic closure upstairs.

Source context 5 commands

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

namespace Yamaguchi26AbfaithfulGalois
open IsLocalRing KummerTheory ValuationTheory.DiscreteValuationField
open ProCGroups.Abelian ProCGroups.FiniteStepSolvableQuotients
open RamificationTheory.HilbertRamification.ValuationSubring
universe u v w x
theorem residueZero_openNormal_faithful_of_inertia_le
    {K : Type u} {Ω : Type v} [Field K] [Field Ω] [Algebra K Ω]
    [IsAlgClosure K Ω] [CharZero K]
    (D : HenselianDVF.{u, w} K) [CharZero D.residueField]
    {Γ : Type x} [LinearOrderedCommGroupWithZero Γ]
    (vΩ : _root_.Valuation Ω Γ) [D.valuation.HasExtension vΩ]
    (hres : IsAbFaithful Gal(AlgebraicClosure D.residueField/D.residueField))
    (N : OpenNormalSubgroup Gal(Ω/K))
    (hI : (henselianResidueAction D.valuation vΩ).ker ≤ (N : Subgroup Gal(Ω/K))) :
    Function.Injective (quotientConjugationTopologicalAbelianizationMap
      (N : Subgroup Gal(Ω/K)))