Module

SPlaces.lean

Nyll.ClassFieldTheory.AlgebraicNumberTheory.Idele.Relative.SPlaces
29 declarations indexed from sourceView source ↗

Finite-place support for relative ideles

This file packages a restricted-product assertion for relative ideles. At every finite place outside a finite set, a relative idele belongs to the actual product of valuation-ring unit groups supplied by the completion decomposition. The resulting supported subgroups are stable under the Galois action and exhaust the full relative idele group.

Declarations

Relative ideles that are integral units in every local tensor factor outside the finite set S.

Source context 7 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
def relativeIdeleLocalTensorDecompositionSupportedSubgroup
    (S : Finset (HeightOneSpectrum (𝓞 K))) :
    Subgroup (RelativeIdeleGroup K L)

Membership in the supported relative-idele subgroup is exactly valuation-ring integrality at every finite place outside S.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [NumberField L] [IsGalois K L] in
theorem mem_relativeIdeleLocalTensorDecompositionSupportedSubgroup_iff
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (z : RelativeIdeleGroup K L) :
    z ∈ relativeIdeleLocalTensorDecompositionSupportedSubgroup
        (K := K) (L := L) S ↔
      ∀ w : HeightOneSpectrum (𝓞 K), w ∉ S →
        RelativeLocalTensorDecompositionIntegralUnitAt
          (K := K) (L := L) w
          (RelativeIdeleGroup.finiteComponent
            (K := K) (L := L) w z)

Enlarging the exceptional set enlarges the supported subgroup.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [NumberField L] [IsGalois K L] in
theorem relativeIdeleLocalTensorDecompositionSupportedSubgroup_mono
    {S T : Finset (HeightOneSpectrum (𝓞 K))}
    (hST : S ⊆ T) :
    relativeIdeleLocalTensorDecompositionSupportedSubgroup
        (K := K) (L := L) S ≤
      relativeIdeleLocalTensorDecompositionSupportedSubgroup
        (K := K) (L := L) T

The explicit coefficient-and-lattice support of a relative idele is an exceptional set witnessing restricted-product integrality.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [IsGalois K L] in
theorem relativeIdele_mem_localTensorDecompositionSupportedSubgroup
    (z : RelativeIdeleGroup K L) :
    z ∈ relativeIdeleLocalTensorDecompositionSupportedSubgroup
        (K := K) (L := L)
        (relativeIdeleLocalTensorDecompositionSupport
          (K := K) (L := L) z)

The finite-support subgroups exhaust the complete relative idele group.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [IsGalois K L] in
theorem iSup_relativeIdeleLocalTensorDecompositionSupportedSubgroup_eq_top :
    ⨆ S : Finset (HeightOneSpectrum (𝓞 K)),
        relativeIdeleLocalTensorDecompositionSupportedSubgroup
          (K := K) (L := L) S =
      (⊤ : Subgroup (RelativeIdeleGroup K L))

The finite local factors of a relative S-idele: unrestricted tensor units on S, and actual local tensor integral units away from S.

Source context 7 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
abbrev RelativeFiniteSPlaceFactors
    (S : Finset (HeightOneSpectrum (𝓞 K)))

The complete local-factor model attached to a finite support.

Source context 7 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
abbrev RelativeIdeleSPlaceFactors
    (S : Finset (HeightOneSpectrum (𝓞 K)))

The same local-factor model after applying the local tensor decomposition at every finite place.

Source context 7 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
abbrev RelativeIdeleSPlaceLocalTensorDecompositionFactors
    (S : Finset (HeightOneSpectrum (𝓞 K)))

The componentwise local tensor decomposition identifies the finite tensor-unit factors with products of the actual completion unit groups, retaining valuation-ring units away from S.

Source context 7 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
def
    relativeIdeleSPlaceFactorsEquivLocalTensorDecomposition
    (S : Finset (HeightOneSpectrum (𝓞 K))) :
    RelativeIdeleSPlaceFactors (K := K) (L := L) S ≃*
      RelativeIdeleSPlaceLocalTensorDecompositionFactors
        (K := K) (L := L) S

Membership in the chosen basis lattice is exactly the coefficient integrality needed by the restricted local-product model.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [NumberField L] [IsGalois K L] in
theorem relativeBasisIntegralAt_repr_mem
    (w : HeightOneSpectrum (𝓞 K))
    (x : w.adicCompletion K ⊗[K] L)
    (hx : RelativeBasisIntegralAt
      (K := K) (L := L) w x)
    (i : RelativeAdeleBasisIndex (K := K) (L := L)) :
    (Algebra.TensorProduct.basis
        (w.adicCompletion K)
        (relativeExtensionBasis
          (K := K) (L := L))).repr x i ∈
      w.adicCompletionIntegers K

Extract all local factors from an integrally supported relative idele.

Source context 7 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
def relativeIdeleSupportedComponents
    (S : Finset (HeightOneSpectrum (𝓞 K))) :
    relativeIdeleLocalTensorDecompositionSupportedSubgroup
        (K := K) (L := L) S →*
      RelativeIdeleSPlaceFactors (K := K) (L := L) S where
  toFun z :=
    ⟨fun w =>
        RelativeIdeleGroup.infiniteComponent
          (K := K) (L := L) w z,
      ⟨fun w =>
          RelativeIdeleGroup.finiteComponent
            (K := K) (L := L) w.1 z,
        fun w =>
          ⟨RelativeIdeleGroup.finiteComponent
              (K := K) (L := L) w.1 z,
            (mem_relativeLocalTensorDecompositionIntegralUnitSubgroup_iff
              (K := K) (L := L) w.1 _).2
              ((mem_relativeIdeleLocalTensorDecompositionSupportedSubgroup_iff
                (K := K) (L := L) S z).1 z.property
                w.1 w.2)⟩⟩⟩
  map_one' := by
    apply Prod.ext
    · funext w
      exact
        map_one
          (RelativeIdeleGroup.infiniteComponent
            (K := K) (L := L) w)
    · apply Prod.ext
      · funext w
        exact
          map_one
            (RelativeIdeleGroup.finiteComponent
              (K := K) (L := L) w.1)
      · funext w
        apply Subtype.ext
        exact
          map_one
            (RelativeIdeleGroup.finiteComponent
              (K := K) (L := L) w.1)
  map_mul' x y := by
    apply Prod.ext
    · funext w
      exact
        map_mul
          (RelativeIdeleGroup.infiniteComponent
            (K := K) (L := L) w)
          (x : RelativeIdeleGroup K L)
          (y : RelativeIdeleGroup K L)
    · apply Prod.ext
      · funext w
        exact
          map_mul
            (RelativeIdeleGroup.finiteComponent
              (K := K) (L := L) w.1)
            (x : RelativeIdeleGroup K L)
            (y : RelativeIdeleGroup K L)
      · funext w
        apply Subtype.ext
        exact
          map_mul
            (RelativeIdeleGroup.finiteComponent
              (K := K) (L := L) w.1)
            (x : RelativeIdeleGroup K L)
            (y : RelativeIdeleGroup K L)

The infinite component of the displayed supported-factor map is the original infinite component of the relative idele.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [NumberField L] [IsGalois K L] in
theorem relativeIdeleSupportedComponents_infinite
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (z : relativeIdeleLocalTensorDecompositionSupportedSubgroup
      (K := K) (L := L) S)
    (w : InfinitePlace K) :
    (relativeIdeleSupportedComponents
      (K := K) (L := L) S z).1 w =
      RelativeIdeleGroup.infiniteComponent
        (K := K) (L := L) w z

At a finite place in S, the displayed supported-factor map is the unrestricted finite component.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [NumberField L] [IsGalois K L] in
theorem relativeIdeleSupportedComponents_inside
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (z : relativeIdeleLocalTensorDecompositionSupportedSubgroup
      (K := K) (L := L) S)
    (w : {w : HeightOneSpectrum (𝓞 K) // w ∈ S}) :
    (relativeIdeleSupportedComponents
      (K := K) (L := L) S z).2.1 w =
      RelativeIdeleGroup.finiteComponent
        (K := K) (L := L) w.1 z

Outside S, coercing the integral factor back to tensor units recovers the original finite component.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [NumberField L] [IsGalois K L] in
theorem relativeIdeleSupportedComponents_outside_coe
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (z : relativeIdeleLocalTensorDecompositionSupportedSubgroup
      (K := K) (L := L) S)
    (w : {w : HeightOneSpectrum (𝓞 K) // w ∉ S}) :
    ((relativeIdeleSupportedComponents
        (K := K) (L := L) S z).2.2 w :
      (w.1.adicCompletion K ⊗[K] L)ˣ) =
      RelativeIdeleGroup.finiteComponent
        (K := K) (L := L) w.1 z

All local components determine a supported relative idele.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [NumberField L] [IsGalois K L] in
theorem relativeIdeleSupportedComponents_injective
    (S : Finset (HeightOneSpectrum (𝓞 K))) :
    Function.Injective
      (relativeIdeleSupportedComponents
        (K := K) (L := L) S)

Assemble the complete S-place factor family as restricted local idele data. Away from S and the finite discriminant set, the converse part of the local tensor decomposition supplies the required coefficient integrality.

Source context 7 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
def relativeLocalIdeleDataOfSPlaceFactors
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (x : RelativeIdeleSPlaceFactors (K := K) (L := L) S) :
    RelativeLocalIdeleData (K := K) (L := L)

The assembled local-idele data has the prescribed infinite component.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [IsGalois K L] in
theorem relativeLocalIdeleDataOfSPlaceFactors_infinite
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (x : RelativeIdeleSPlaceFactors (K := K) (L := L) S)
    (w : InfinitePlace K) :
    (relativeLocalIdeleDataOfSPlaceFactors
      (K := K) (L := L) S x).infinite w = x.1 w

At a finite place in S, the assembled local-idele data has the prescribed unrestricted component.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [IsGalois K L] in
theorem relativeLocalIdeleDataOfSPlaceFactors_finite_inside
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (x : RelativeIdeleSPlaceFactors (K := K) (L := L) S)
    (w : HeightOneSpectrum (𝓞 K))
    (hw : w ∈ S) :
    (relativeLocalIdeleDataOfSPlaceFactors
      (K := K) (L := L) S x).finite w =
        x.2.1 ⟨w, hw⟩

At a finite place outside S, the assembled local-idele data is the coercion of the prescribed integral component.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [IsGalois K L] in
theorem relativeLocalIdeleDataOfSPlaceFactors_finite_outside
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (x : RelativeIdeleSPlaceFactors (K := K) (L := L) S)
    (w : HeightOneSpectrum (𝓞 K))
    (hw : w ∉ S) :
    (relativeLocalIdeleDataOfSPlaceFactors
      (K := K) (L := L) S x).finite w =
        (x.2.2 ⟨w, hw⟩ :
          (w.adicCompletion K ⊗[K] L)ˣ)

Assemble prescribed local factors into the actual supported relative idele.

Source context 7 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
def relativeIdeleOfSPlaceFactors
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (x : RelativeIdeleSPlaceFactors (K := K) (L := L) S) :
    relativeIdeleLocalTensorDecompositionSupportedSubgroup
      (K := K) (L := L) S

The relative idele assembled from displayed S-place factors has the prescribed infinite component.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [IsGalois K L] in
theorem relativeIdeleOfSPlaceFactors_infiniteComponent
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (x : RelativeIdeleSPlaceFactors (K := K) (L := L) S)
    (w : InfinitePlace K) :
    RelativeIdeleGroup.infiniteComponent
        (K := K) (L := L) w
        (relativeIdeleOfSPlaceFactors
          (K := K) (L := L) S x) =
      x.1 w

At a finite place in S, the assembled relative idele has the prescribed unrestricted component.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [IsGalois K L] in
theorem relativeIdeleOfSPlaceFactors_finiteComponent_inside
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (x : RelativeIdeleSPlaceFactors (K := K) (L := L) S)
    (w : HeightOneSpectrum (𝓞 K))
    (hw : w ∈ S) :
    RelativeIdeleGroup.finiteComponent
        (K := K) (L := L) w
        (relativeIdeleOfSPlaceFactors
          (K := K) (L := L) S x) =
      x.2.1 ⟨w, hw⟩

At a finite place outside S, the assembled relative idele has the coercion of the prescribed integral component.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [IsGalois K L] in
theorem relativeIdeleOfSPlaceFactors_finiteComponent_outside
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (x : RelativeIdeleSPlaceFactors (K := K) (L := L) S)
    (w : HeightOneSpectrum (𝓞 K))
    (hw : w ∉ S) :
    RelativeIdeleGroup.finiteComponent
        (K := K) (L := L) w
        (relativeIdeleOfSPlaceFactors
          (K := K) (L := L) S x) =
      (x.2.2 ⟨w, hw⟩ :
        (w.adicCompletion K ⊗[K] L)ˣ)

Every complete family of local factors is realized by a supported relative idele.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [IsGalois K L] in
theorem relativeIdeleSupportedComponents_surjective
    (S : Finset (HeightOneSpectrum (𝓞 K))) :
    Function.Surjective
      (relativeIdeleSupportedComponents
        (K := K) (L := L) S)

The exact relative finite-support decomposition:

I_{L/K}^S is the product of all archimedean tensor-unit factors, the unrestricted finite tensor-unit factors over S, and the genuine valuation-ring unit factors away from S.

Source context 7 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
def relativeIdeleSupportedEquivSPlaceFactors
    (S : Finset (HeightOneSpectrum (𝓞 K))) :
    relativeIdeleLocalTensorDecompositionSupportedSubgroup
        (K := K) (L := L) S ≃*
      RelativeIdeleSPlaceFactors (K := K) (L := L) S

The natural Galois action restricts to every finite-support subgroup.

Source context 7 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
def
    relativeIdeleLocalTensorDecompositionSupportedSubgroupAction
    (S : Finset (HeightOneSpectrum (𝓞 K))) :
    MulDistribMulAction
      (L ≃ₐ[K] L)
      (relativeIdeleLocalTensorDecompositionSupportedSubgroup
        (K := K) (L := L) S)

Coercing the supported-subgroup action to the relative idele group recovers the ambient Galois action.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [NumberField L] [IsGalois K L] in
theorem
    relativeIdeleLocalTensorDecompositionSupportedSubgroupAction_coe
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (σ : L ≃ₐ[K] L)
    (z : relativeIdeleLocalTensorDecompositionSupportedSubgroup
      (K := K) (L := L) S) :
    letI :=
      relativeIdeleLocalTensorDecompositionSupportedSubgroupAction
        (K := K) (L := L) S
    ((σ • z :
        relativeIdeleLocalTensorDecompositionSupportedSubgroup
          (K := K) (L := L) S) :
      RelativeIdeleGroup K L) =
      letI :=
        relativeIdeleRestrictedMulDistribMulAction
          (K := K) (L := L)
      σ • (z : RelativeIdeleGroup K L) :=
  rfl

Coordinatewise Galois action on the complete local-factor model.

Source context 7 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
def relativeIdeleSPlaceFactorsAction
    (S : Finset (HeightOneSpectrum (𝓞 K))) :
    MulDistribMulAction
      (L ≃ₐ[K] L)
      (RelativeIdeleSPlaceFactors
        (K := K) (L := L) S)

The complete local-component map is equivariant.

Source context 8 commands

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

open scoped NumberField TensorProduct
open NumberField IsDedekindDomain
noncomputable section
open CyclicCohomology
open AlgebraicNumberTheory.Valuations
universe u v
variable
    {K : Type u} {L : Type v}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
omit [NumberField L] [IsGalois K L] in
theorem relativeIdeleSupportedComponents_smul
    (S : Finset (HeightOneSpectrum (𝓞 K)))
    (σ : L ≃ₐ[K] L)
    (z : relativeIdeleLocalTensorDecompositionSupportedSubgroup
      (K := K) (L := L) S) :
    letI :=
      relativeIdeleLocalTensorDecompositionSupportedSubgroupAction
        (K := K) (L := L) S
    letI :=
      relativeIdeleSPlaceFactorsAction
        (K := K) (L := L) S
    relativeIdeleSupportedComponents
        (K := K) (L := L) S (σ • z) =
      σ • relativeIdeleSupportedComponents
        (K := K) (L := L) S z := by
  let :=
    relativeIdeleLocalTensorDecompositionSupportedSubgroupAction
      (K := K) (L := L) S
  let :=
    relativeIdeleSPlaceFactorsAction
      (K := K) (L := L) S
  apply Prod.ext
  · funext w
    let :=
      scalarTensorUnitsAction
        (K := K) (L := L) (A := w.Completion)
    exact
      RelativeIdeleGroup.infiniteComponent_smul
        (K := K) (L := L) w σ z
  · apply Prod.ext
    · funext w
      let :=
        scalarTensorUnitsAction
          (K := K) (L := L)
          (A := w.1.adicCompletion K)
      exact
        RelativeIdeleGroup.finiteComponent_smul
          (K := K) (L := L) w.1 σ z
    · funext w
      apply Subtype.ext
      let :=
        scalarTensorUnitsAction
          (K := K) (L := L)
          (A := w.1.adicCompletion K)
      exact
        RelativeIdeleGroup.finiteComponent_smul
          (K := K) (L := L) w.1 σ z