Module

ChosenPlaceIntegralBlock.lean

Nyll.ClassFieldTheory.AlgebraicNumberTheory.Idele.Cohomology.SPlaces.OutsideIntegralInduced.ChosenPlaceIntegralBlock
1 declaration indexed from sourceView source ↗

Equivariance facade for the integral induced block

This file combines the independent induced-block and tensor-block equivariance lemmas into the transport used by the cohomology layer.

Declarations

The integral tensor-to-induced-module equivalence is equivariant for the full global Galois action.

Source context 12 commands

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

open scoped NumberField TensorProduct ValuativeRel NNReal
open NumberField IsDedekindDomain
noncomputable section
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open LocalClassFieldTheory
open LocalFieldTheory
open CyclicCohomology.ProfiniteCohomology.Herbrand
open CyclicCohomology
variable
    {K : Type} {L : Type}
    [Field K] [NumberField K]
    [Field L] [NumberField L] [Algebra K L]
    [FiniteDimensional K L] [IsGalois K L]
section ChosenFinitePlace
omit [NumberField L] in
theorem
    relativeLocalTensorDecompositionIntegralUnitSubgroupEquivInducedIntegerUnits_smul
    (w₀ : HeightOneSpectrum (𝓞 K))
    (τ : L ≃ₐ[K] L)
    (x : relativeLocalTensorDecompositionIntegralUnitSubgroup
      (K := K) (L := L) w₀) :
    letI :=
      relativeLocalTensorDecompositionIntegralUnitSubgroupAction
        (K := K) (L := L) w₀
    letI :=
      chosenFinitePlaceInducedIntegerUnitsAction
        (K := K) (L := L) w₀
    relativeLocalTensorDecompositionIntegralUnitSubgroupEquivInducedIntegerUnits
        (K := K) (L := L) w₀ (τ • x) =
      τ •
        (relativeLocalTensorDecompositionIntegralUnitSubgroupEquivInducedIntegerUnits
          (K := K) (L := L) w₀ x) := by
  let :=
    relativeLocalTensorDecompositionIntegralUnitSubgroupAction
      (K := K) (L := L) w₀
  let :=
    chosenFinitePlaceInducedIntegerUnitsAction
      (K := K) (L := L) w₀
  let :=
    chosenFinitePlaceLocalPlaceBlockAction
      (K := K) (L := L) w₀
  apply
    chosenFinitePlaceIntegralInducedBlockToLocalPlaceBlock_injective
      (K := K) (L := L) w₀
  calc
    chosenFinitePlaceIntegralInducedBlockToLocalPlaceBlock
          (K := K) (L := L) w₀
          (relativeLocalTensorDecompositionIntegralUnitSubgroupEquivInducedIntegerUnits
            (K := K) (L := L) w₀
            ((relativeLocalTensorDecompositionIntegralUnitSubgroupAction
              (K := K) (L := L) w₀).smul τ x)) =
        finitePlaceTensorUnitsEquivLocalPlaceBlock
          (K := K) (L := L) w₀
          (chosenFinitePlaceExtension (L := L) w₀)
          (((relativeLocalTensorDecompositionIntegralUnitSubgroupAction
              (K := K) (L := L) w₀).smul τ x :
              relativeLocalTensorDecompositionIntegralUnitSubgroup
                (K := K) (L := L) w₀) :
            (w₀.adicCompletion K ⊗[K] L)ˣ) :=
      chosenFinitePlaceIntegralInducedBlockToLocalPlaceBlock_equiv_apply
        (K := K) (L := L) w₀
        ((relativeLocalTensorDecompositionIntegralUnitSubgroupAction
          (K := K) (L := L) w₀).smul τ x)
    _ =
        (chosenFinitePlaceLocalPlaceBlockAction
          (K := K) (L := L) w₀).smul τ
          (finitePlaceTensorUnitsEquivLocalPlaceBlock
            (K := K) (L := L) w₀
            (chosenFinitePlaceExtension (L := L) w₀)
            (x : (w₀.adicCompletion K ⊗[K] L)ˣ)) :=
      finitePlaceTensorUnitsEquivLocalPlaceBlock_restricted_smul
        (K := K) (L := L) w₀ τ x
    _ =
        (chosenFinitePlaceLocalPlaceBlockAction
          (K := K) (L := L) w₀).smul τ
          (chosenFinitePlaceIntegralInducedBlockToLocalPlaceBlock
            (K := K) (L := L) w₀
            (relativeLocalTensorDecompositionIntegralUnitSubgroupEquivInducedIntegerUnits
              (K := K) (L := L) w₀ x)) :=
      congrArg
        (fun z :
            ChosenFinitePlaceLocalPlaceBlock
              (K := K) (L := L) w₀ =>
          (chosenFinitePlaceLocalPlaceBlockAction
            (K := K) (L := L) w₀).smul τ z)
        (chosenFinitePlaceIntegralInducedBlockToLocalPlaceBlock_equiv_apply
          (K := K) (L := L) w₀ x).symm
    _ =
        chosenFinitePlaceIntegralInducedBlockToLocalPlaceBlock
          (K := K) (L := L) w₀
          ((chosenFinitePlaceInducedIntegerUnitsAction
            (K := K) (L := L) w₀).smul τ
            (relativeLocalTensorDecompositionIntegralUnitSubgroupEquivInducedIntegerUnits
              (K := K) (L := L) w₀ x)) :=
      (chosenFinitePlaceIntegralInducedBlockToLocalPlaceBlock_smul
        (K := K) (L := L) w₀ τ
        (relativeLocalTensorDecompositionIntegralUnitSubgroupEquivInducedIntegerUnits
          (K := K) (L := L) w₀ x)).symm