Module

LocalNorm.lean

Nyll.ClassFieldTheory.AlgebraicNumberTheory.Completion.UnramifiedComparison.LocalNorm
1 declaration indexed from sourceView source ↗

Local norms at an unramified chosen finite place

This file proves that the concrete adic integer units lie in the actual local norm subgroup of the chosen localized completion.

Declarations

At a chosen finite place which is unramified in L, every concrete adic integer unit is an actual norm from the chosen localization.

Source context 8 commands

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

open scoped NumberField NNReal ValuativeRel
open NumberField IsDedekindDomain
noncomputable section
open AlgebraicNumberTheory.Valuations
open LocalClassFieldTheory
open LocalFieldTheory
open LocalFieldTheory.IsNonarchimedeanLocalField
variable
    {K L : Type}
    [Field K] [NumberField K]
    [Field L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
theorem adicCompletionIntegerUnits_le_chosenFinitePlaceLocalNormSubgroup
    (v₀ : HeightOneSpectrum (𝓞 K))
    (hunram :
      ChosenFinitePlaceIsUnramified
        (K := K) (L := L) v₀) :
    (v₀.adicCompletionIntegers K).units ≤
      chosenFinitePlaceLocalNormSubgroup
        (K := K) (L := L) v₀