Module

NormContainment.lean

Nyll.ClassFieldTheory.GlobalClassFieldTheory.ClassFieldAxiom.IdeleClassPowerLocalUnitQuotient.NormContainment
2 declarations indexed from sourceView source ↗

Norm containment for idele power-local-unit subgroups

This file proves that the concrete local-condition subgroup lies in the global idele norm range, and descends that inclusion to idele classes.

Imports16
Imported by6

Declarations

GlobalClassFieldTheory.ClassFieldAxiom.idelePowerLocalUnitSubgroup_le_relativeIdeleNorm_range

The idele norm inclusion h(S,T) ⊆ N_{L/K} I_L.

Source context 10 commands

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

open scoped NumberField NNReal ValuativeRel TensorProduct
open NumberField IsDedekindDomain
open AlgebraicNumberTheory.Valuations
open KummerTheory
open LocalFieldTheory
open LocalFieldTheory.IsNonarchimedeanLocalField
noncomputable section
namespace GlobalClassFieldTheory.ClassFieldAxiom
variable {K L : Type} [Field K] [NumberField K] [Field L] [NumberField L]
    [Algebra K L] [FiniteDimensional K L] [IsGalois K L]
open scoped Classical in
theorem idelePowerLocalUnitSubgroup_le_relativeIdeleNorm_range
    (n : ℕ+) (r : ℕ)
    (eG :
      (L ≃ₐ[K] L) ≃*
        (Fin r → Multiplicative (ZMod (n : ℕ))))
    (S T : Finset (HeightOneSpectrum (𝓞 K)))
    (harch :
      Even (n : ℕ) ∨
        ∀ w : InfinitePlace K, ¬ w.IsReal)
    (hT :
      ∀ v, v ∈ T →
        _root_.FinitePlaceSplitsCompletely
          (K := K) (L := L) v)
    (hAway :
      ∀ v, v ∉ S ∪ T →
        _root_.ChosenFinitePlaceIsUnramified
          (K := K) (L := L) v) :
    idelePowerLocalUnitSubgroup (K := K) n S T ≤
      (RelativeIdeleGroup.norm K L).range
GlobalClassFieldTheory.ClassFieldAxiom.ideleClassPowerLocalUnitSubgroup_le_ideleClassNorm_range

The induced norm inclusion on idele class groups: N_{L/K} C_L ⊇ C_K(S,T).

Source context 10 commands

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

open scoped NumberField NNReal ValuativeRel TensorProduct
open NumberField IsDedekindDomain
open AlgebraicNumberTheory.Valuations
open KummerTheory
open LocalFieldTheory
open LocalFieldTheory.IsNonarchimedeanLocalField
noncomputable section
namespace GlobalClassFieldTheory.ClassFieldAxiom
variable {K L : Type} [Field K] [NumberField K] [Field L] [NumberField L]
    [Algebra K L] [FiniteDimensional K L] [IsGalois K L]
open scoped Classical in
theorem ideleClassPowerLocalUnitSubgroup_le_ideleClassNorm_range
    (n : ℕ+) (r : ℕ)
    (eG :
      (L ≃ₐ[K] L) ≃*
        (Fin r → Multiplicative (ZMod (n : ℕ))))
    (S T : Finset (HeightOneSpectrum (𝓞 K)))
    (harch :
      Even (n : ℕ) ∨
        ∀ w : InfinitePlace K, ¬ w.IsReal)
    (hT :
      ∀ v, v ∈ T →
        _root_.FinitePlaceSplitsCompletely
          (K := K) (L := L) v)
    (hAway :
      ∀ v, v ∉ S ∪ T →
        _root_.ChosenFinitePlaceIsUnramified
          (K := K) (L := L) v) :
    ideleClassPowerLocalUnitSubgroup (K := K) n S T ≤
      (RelativeIdeleGroup.Cohomology.ideleClassNorm K L).range