Module

InfiniteAlgEquiv.lean

Nyll.ClassFieldTheory.AlgebraicNumberTheory.Idele.ClassGroup.InfiniteAlgEquiv
5 declarations indexed from sourceView source ↗

Infinite completions under a number-field equivalence

The completion maps along an isomorphism of number fields are mutually inverse. This is the archimedean local input for the topology of adeleCongr.

Declarations

The map between the completions at corresponding infinite places.

Source context 5 commands

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

open scoped NumberField TensorProduct
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]
def infinitePlaceCompletionCongrHom
    (e : K ≃ₐ[ℚ] M) (W : InfinitePlace M) :
    ((ClassFieldTheory.infinitePlaceEquivOfRingEquiv e.toRingEquiv).symm W).Completion →+*
      W.Completion

The archimedean completion map is continuous.

Source context 5 commands

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

open scoped NumberField TensorProduct
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 infinitePlaceCompletionCongrHom_continuous
    (e : K ≃ₐ[ℚ] M) (W : InfinitePlace M) :
    Continuous (infinitePlaceCompletionCongrHom e W)

Transport along a field isomorphism is an equivalence of the corresponding infinite-place completions.

Source context 5 commands

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

open scoped NumberField TensorProduct
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]
def infinitePlaceCompletionCongrEquiv
    (e : K ≃ₐ[ℚ] M) (W : InfinitePlace M) :
    ((ClassFieldTheory.infinitePlaceEquivOfRingEquiv e.toRingEquiv).symm W).Completion ≃+*
      W.Completion

The completion map agrees with the number-field equivalence on elements of the number field.

Source context 5 commands

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

open scoped NumberField TensorProduct
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 infinitePlaceCompletionCongrHom_algebraMap
    (e : K ≃ₐ[ℚ] M) (W : InfinitePlace M) (x : K) :
    infinitePlaceCompletionCongrHom e W
        (algebraMap K
          ((ClassFieldTheory.infinitePlaceEquivOfRingEquiv e.toRingEquiv).symm W).Completion x) =
      algebraMap M W.Completion (e x)

On infinite coordinates, adeleCongr is the completion map at the corresponding infinite place.

Source context 5 commands

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

open scoped NumberField TensorProduct
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 adeleCongr_infiniteComponent
    (e : K ≃ₐ[ℚ] M)
    (a : NumberField.AdeleRing (𝓞 K) K)
    (W : InfinitePlace M) :
    (adeleCongr e a).1 W =
      infinitePlaceCompletionCongrHom e W
        (a.1 ((ClassFieldTheory.infinitePlaceEquivOfRingEquiv e.toRingEquiv).symm W))