Module

AlgEquivFiniteIntegral.lean

Nyll.ClassFieldTheory.AlgebraicNumberTheory.Idele.ClassGroup.AlgEquivFiniteIntegral
1 declaration indexed from sourceView source ↗

Integral finite completions under a number-field equivalence

The finite-completion map associated with a field equivalence preserves the local valuation subring. This is the restricted-product compatibility needed for continuity of adelic transport.

Declarations

Corresponding finite-completion maps carry local integers to local integers.

Source context 5 commands

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

open scoped NumberField
open NumberField IsDedekindDomain
noncomputable section
universe u v
variable {K : Type u} {M : Type v}
  [Field K] [NumberField K] [Algebra ℚ K]
  [Field M] [NumberField M] [Algebra ℚ M]
theorem finitePlaceAdicCompletionCongrHom_mapsToIntegers
    (e : K ≃ₐ[ℚ] M) (W : HeightOneSpectrum (𝓞 M)) :
    Set.MapsTo (finitePlaceAdicCompletionCongrHom e W)
      (((finitePlaceCongr e).symm W).adicCompletionIntegers K :
        Set (((finitePlaceCongr e).symm W).adicCompletion K))
      (W.adicCompletionIntegers M : Set (W.adicCompletion M))