Module

FinitePlaceAbsoluteArtinCompatibility.lean

Nyll.SawinTotallyRealTowers.UnramifiedProPRelationRank.Radical.FinitePlaceAbsoluteArtinCompatibility
11 declarations indexed from sourceView source ↗

Actual global--local Artin compatibility for finite-place characters

The selected algebraic-localization embedding first gives equality of the finite Artin actions. Finite projections identify the maximal-abelian global value, and semilinear naturality transports its representative to the concrete adic completion. Consequently actual global character restriction and local reciprocity evaluate to the same value, without roots of unity in the base field.

Declarations

ClassFieldTower.Martinet.Shafarevich.finitePlaceAlgebraicClosureToAbsoluteCompletion

The selected global algebraic closure embedded into the absolute-value completion model used by finite global reciprocity.

Source context 5 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField IsDedekindDomain LocalClassFieldTheory GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F]
variable (v : HeightOneSpectrum (RingOfIntegers F))
def finitePlaceAlgebraicClosureToAbsoluteCompletion :
    AlgebraicClosure F →ₐ[F] AlgebraicClosure (HeightOneSpectrum.adicAbv F v).Completion where
  toRingHom := (finitePlaceCompletionAlgebraicClosureRingEquiv F v).symm.toRingHom.comp
    (finitePlaceAlgebraicClosureEmbedding F v)
  commutes' x := by
    apply (finitePlaceCompletionAlgebraicClosureRingEquiv F v).injective
    change (finitePlaceCompletionAlgebraicClosureRingEquiv F v)
      ((finitePlaceCompletionAlgebraicClosureRingEquiv F v).symm
        (finitePlaceAlgebraicClosureEmbedding F v (algebraMap F (AlgebraicClosure F) x))) = _
    rw [RingEquiv.apply_symm_apply, finitePlaceAlgebraicClosureEmbedding_algebraMap]
    change _ = finitePlaceCompletionAlgebraicClosureRingEquiv F v
      (algebraMap (HeightOneSpectrum.adicAbv F v).Completion _ (algebraMap F _ x))
    rw [finitePlaceCompletionAlgebraicClosureRingEquiv_algebraMap,
      (relativeFinitePlaceCompletionAlgEquiv v).commutes]
ClassFieldTower.Martinet.Shafarevich.finitePlaceAlgebraicClosureToAbsoluteCompletion_action

The same embedding intertwines the actual decomposition action.

Source context 5 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField IsDedekindDomain LocalClassFieldTheory GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F]
variable (v : HeightOneSpectrum (RingOfIntegers F))
theorem finitePlaceAlgebraicClosureToAbsoluteCompletion_action
    (sigma : Gal(AlgebraicClosure
      (HeightOneSpectrum.adicAbv F v).Completion/(HeightOneSpectrum.adicAbv F v).Completion))
    (x : AlgebraicClosure F) :
    sigma (finitePlaceAlgebraicClosureToAbsoluteCompletion F v x) =
      finitePlaceAlgebraicClosureToAbsoluteCompletion F v
        (((finitePlaceDecompositionGroupContinuousMulEquivAbsoluteGaloisGroup F v).symm
          sigma).val x)
ClassFieldTower.Martinet.Shafarevich.finitePlaceAbsoluteCompatibilitySourceValuativeRel
Source context 5 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField IsDedekindDomain LocalClassFieldTheory GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F]
variable (v : HeightOneSpectrum (RingOfIntegers F))
instance finitePlaceAbsoluteCompatibilitySourceValuativeRel :
    ValuativeRel (HeightOneSpectrum.adicAbv F v).Completion
ClassFieldTower.Martinet.Shafarevich.finitePlaceAbsoluteCompatibilitySourceLocalField
Source context 6 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField IsDedekindDomain LocalClassFieldTheory GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F]
variable (v : HeightOneSpectrum (RingOfIntegers F))
local instance finitePlaceAbsoluteCompatibilitySourceValuativeRel :
    ValuativeRel (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionValuativeRel v
instance finitePlaceAbsoluteCompatibilitySourceLocalField :
    IsNonarchimedeanLocalField (HeightOneSpectrum.adicAbv F v).Completion
ClassFieldTower.Martinet.Shafarevich.finitePlaceAbsoluteArtin_lift_maximalAbelian

An actual local Artin representative restricts to the one-place maximal abelian global Artin value.

Source context 7 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField IsDedekindDomain LocalClassFieldTheory GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F]
variable (v : HeightOneSpectrum (RingOfIntegers F))
local instance finitePlaceAbsoluteCompatibilitySourceValuativeRel :
    ValuativeRel (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionValuativeRel v
local instance finitePlaceAbsoluteCompatibilitySourceLocalField :
    IsNonarchimedeanLocalField (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionIsNonarchimedeanLocalField v
theorem finitePlaceAbsoluteArtin_lift_maximalAbelian
    (a : (v.adicCompletion F)ˣ)
    (sigma : Gal(AlgebraicClosure
      (HeightOneSpectrum.adicAbv F v).Completion/(HeightOneSpectrum.adicAbv F v).Completion))
    (hsigma : (QuotientGroup.mk
        (show Field.absoluteGaloisGroup (HeightOneSpectrum.adicAbv F v).Completion from sigma) :
        Field.absoluteGaloisGroupAbelianization (HeightOneSpectrum.adicAbv F v).Completion) =
      absoluteLocalArtinMap (HeightOneSpectrum.adicAbv F v).Completion
        (finitePlaceLocalArtinInput v a)) :
    globalMaximalAbelianRestriction F
        ((finitePlaceDecompositionGroupContinuousMulEquivAbsoluteGaloisGroup F v).symm sigma).val =
      maximalAbelianGlobalArtin F (IdeleGroup.finitePlaceIdeleClass v a) := by
  let delta := (finitePlaceDecompositionGroupContinuousMulEquivAbsoluteGaloisGroup F v).symm sigma
  apply maximalAbelianGalois_ext_of_finite_restrictions F
  intro E
  let : NumberField E := NumberField.of_module_finite F E
  rw [maximalAbelianGlobalArtin_finitePlace_finiteProjection]
  let i : E →ₐ[F] AlgebraicClosure F :=
    (separableClosure F (AlgebraicClosure F)).val.comp
      ((_root_.maximalAbelianExtension F).val.comp E.val)
  apply AlgEquiv.ext
  intro z
  apply i.injective
  have hfinite := finitePlaceAbsoluteArtin_lift_action F E v
    ((finitePlaceAlgebraicClosureToAbsoluteCompletion F v).comp i) a sigma hsigma z
  have haction := finitePlaceAlgebraicClosureToAbsoluteCompletion_action F v sigma (i z)
  have hglobal : delta.val (i z) =
      i (chosenFinitePlaceArtinMonoidHom (K := F) (L := E) v a z) :=
    (finitePlaceAlgebraicClosureToAbsoluteCompletion F v).injective
      (haction.symm.trans hfinite)
  let s := RamificationTheory.Field.absoluteGaloisGroup.separableClosureContinuousMulEquiv
    F delta.val
  have hE := AlgEquiv.restrictNormal_commutes (globalMaximalAbelianRestriction F delta.val) E z
  have hM := AlgEquiv.restrictNormal_commutes s (_root_.maximalAbelianExtension F)
    (algebraMap E (_root_.maximalAbelianExtension F) z)
  have hrestriction : i (AlgEquiv.restrictNormalHom E
      (globalMaximalAbelianRestriction F delta.val) z) = delta.val (i z) := by
    exact (congrArg (fun x : _root_.maximalAbelianExtension F ↦
        (((x : SeparableClosure F) : AlgebraicClosure F))) hE).trans
      (congrArg (fun x : SeparableClosure F ↦ (x : AlgebraicClosure F)) hM)
  exact hrestriction.trans hglobal
ClassFieldTower.Martinet.Shafarevich.finitePlaceAbsoluteCompatibilityTargetValuativeRel
Source context 7 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField IsDedekindDomain LocalClassFieldTheory GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F]
variable (v : HeightOneSpectrum (RingOfIntegers F))
local instance finitePlaceAbsoluteCompatibilitySourceValuativeRel :
    ValuativeRel (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionValuativeRel v
local instance finitePlaceAbsoluteCompatibilitySourceLocalField :
    IsNonarchimedeanLocalField (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionIsNonarchimedeanLocalField v
instance finitePlaceAbsoluteCompatibilityTargetValuativeRel :
    ValuativeRel (v.adicCompletion F)
ClassFieldTower.Martinet.Shafarevich.finitePlaceAbsoluteCompatibilityTargetLocalField
Source context 8 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField IsDedekindDomain LocalClassFieldTheory GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F]
variable (v : HeightOneSpectrum (RingOfIntegers F))
local instance finitePlaceAbsoluteCompatibilitySourceValuativeRel :
    ValuativeRel (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionValuativeRel v
local instance finitePlaceAbsoluteCompatibilitySourceLocalField :
    IsNonarchimedeanLocalField (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionIsNonarchimedeanLocalField v
local instance finitePlaceAbsoluteCompatibilityTargetValuativeRel :
    ValuativeRel (v.adicCompletion F) := finitePlaceAdicCompletionValuativeRel F v
instance finitePlaceAbsoluteCompatibilityTargetLocalField :
    IsNonarchimedeanLocalField (v.adicCompletion F)
ClassFieldTower.Martinet.Shafarevich.finitePlaceCompletionArtin_lift

The actual completion comparison sends an Artin representative to one for the concrete adic completion.

Source context 9 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField IsDedekindDomain LocalClassFieldTheory GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F]
variable (v : HeightOneSpectrum (RingOfIntegers F))
local instance finitePlaceAbsoluteCompatibilitySourceValuativeRel :
    ValuativeRel (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionValuativeRel v
local instance finitePlaceAbsoluteCompatibilitySourceLocalField :
    IsNonarchimedeanLocalField (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionIsNonarchimedeanLocalField v
local instance finitePlaceAbsoluteCompatibilityTargetValuativeRel :
    ValuativeRel (v.adicCompletion F) := finitePlaceAdicCompletionValuativeRel F v
local instance finitePlaceAbsoluteCompatibilityTargetLocalField :
    IsNonarchimedeanLocalField (v.adicCompletion F) :=
  finitePlaceAdicCompletionIsNonarchimedeanLocalField F v
theorem finitePlaceCompletionArtin_lift
    (a : (v.adicCompletion F)ˣ)
    (sigma : Gal(AlgebraicClosure
      (HeightOneSpectrum.adicAbv F v).Completion/(HeightOneSpectrum.adicAbv F v).Completion))
    (hsigma : (QuotientGroup.mk
        (show Field.absoluteGaloisGroup (HeightOneSpectrum.adicAbv F v).Completion from sigma) :
        Field.absoluteGaloisGroupAbelianization (HeightOneSpectrum.adicAbv F v).Completion) =
      absoluteLocalArtinMap (HeightOneSpectrum.adicAbv F v).Completion
        (finitePlaceLocalArtinInput v a)) :
    (QuotientGroup.mk (finitePlaceCompletionAbsoluteGaloisContinuousMulEquiv F v sigma) :
      Field.absoluteGaloisGroupAbelianization (v.adicCompletion F)) =
      absoluteLocalArtinMap (v.adicCompletion F) a := by
  let C := (HeightOneSpectrum.adicAbv F v).Completion
  let c := (relativeFinitePlaceCompletionAlgEquiv v).toRingEquiv
  have h := absoluteLocalArtinMap_semilinear_lift C (v.adicCompletion F) c
    (finitePlaceCompletionAlgebraicClosureRingEquiv F v)
    (finitePlaceCompletionAlgebraicClosureRingEquiv_algebraMap F v)
    (finitePlaceCompletion_semilinearValuationCompatible F v)
    (finitePlaceLocalArtinInput v a) sigma hsigma
  have ha : Units.map c.toMonoidHom (finitePlaceLocalArtinInput v a) = a := by
    have hc : c = finitePlaceCompletionRingEquiv v :=
      (finitePlaceCompletionRingEquiv_eq_relative v).symm
    rw [hc]
    exact (finitePlaceCompletionUnitsContinuousMulEquiv v).apply_symm_apply a
  rw [ha] at h
  exact h
ClassFieldTower.Martinet.Shafarevich.finitePlaceAbsoluteCompatibilityCharacterTopology
Source context 10 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField IsDedekindDomain LocalClassFieldTheory GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F]
variable (v : HeightOneSpectrum (RingOfIntegers F))
local instance finitePlaceAbsoluteCompatibilitySourceValuativeRel :
    ValuativeRel (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionValuativeRel v
local instance finitePlaceAbsoluteCompatibilitySourceLocalField :
    IsNonarchimedeanLocalField (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionIsNonarchimedeanLocalField v
local instance finitePlaceAbsoluteCompatibilityTargetValuativeRel :
    ValuativeRel (v.adicCompletion F) := finitePlaceAdicCompletionValuativeRel F v
local instance finitePlaceAbsoluteCompatibilityTargetLocalField :
    IsNonarchimedeanLocalField (v.adicCompletion F) :=
  finitePlaceAdicCompletionIsNonarchimedeanLocalField F v
variable (p : ℕ) [Fact p.Prime]
instance finitePlaceAbsoluteCompatibilityCharacterTopology :
    TopologicalSpace (Multiplicative (ZMod p))
ClassFieldTower.Martinet.Shafarevich.finitePlaceAbsoluteCompatibilityCharacterDiscreteTopology
Source context 11 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField IsDedekindDomain LocalClassFieldTheory GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F]
variable (v : HeightOneSpectrum (RingOfIntegers F))
local instance finitePlaceAbsoluteCompatibilitySourceValuativeRel :
    ValuativeRel (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionValuativeRel v
local instance finitePlaceAbsoluteCompatibilitySourceLocalField :
    IsNonarchimedeanLocalField (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionIsNonarchimedeanLocalField v
local instance finitePlaceAbsoluteCompatibilityTargetValuativeRel :
    ValuativeRel (v.adicCompletion F) := finitePlaceAdicCompletionValuativeRel F v
local instance finitePlaceAbsoluteCompatibilityTargetLocalField :
    IsNonarchimedeanLocalField (v.adicCompletion F) :=
  finitePlaceAdicCompletionIsNonarchimedeanLocalField F v
variable (p : ℕ) [Fact p.Prime]
local instance finitePlaceAbsoluteCompatibilityCharacterTopology :
    TopologicalSpace (Multiplicative (ZMod p)) := ⊥
instance finitePlaceAbsoluteCompatibilityCharacterDiscreteTopology :
    DiscreteTopology (Multiplicative (ZMod p))
ClassFieldTower.Martinet.Shafarevich.localReciprocityUnitCharacter_globalMaximalAbelian

Actual global--local Artin compatibility evaluated by a continuous mod-p character of the maximal abelian global extension.

Source context 12 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField IsDedekindDomain LocalClassFieldTheory GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F]
variable (v : HeightOneSpectrum (RingOfIntegers F))
local instance finitePlaceAbsoluteCompatibilitySourceValuativeRel :
    ValuativeRel (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionValuativeRel v
local instance finitePlaceAbsoluteCompatibilitySourceLocalField :
    IsNonarchimedeanLocalField (HeightOneSpectrum.adicAbv F v).Completion :=
  finitePlaceLocalArtinCompletionIsNonarchimedeanLocalField v
local instance finitePlaceAbsoluteCompatibilityTargetValuativeRel :
    ValuativeRel (v.adicCompletion F) := finitePlaceAdicCompletionValuativeRel F v
local instance finitePlaceAbsoluteCompatibilityTargetLocalField :
    IsNonarchimedeanLocalField (v.adicCompletion F) :=
  finitePlaceAdicCompletionIsNonarchimedeanLocalField F v
variable (p : ℕ) [Fact p.Prime]
local instance finitePlaceAbsoluteCompatibilityCharacterTopology :
    TopologicalSpace (Multiplicative (ZMod p)) := ⊥
local instance finitePlaceAbsoluteCompatibilityCharacterDiscreteTopology :
    DiscreteTopology (Multiplicative (ZMod p)) := discreteTopology_bot _
theorem localReciprocityUnitCharacter_globalMaximalAbelian
    (psi : Gal(_root_.maximalAbelianExtension F/F) →ₜ* Multiplicative (ZMod p))
    (a : (v.adicCompletion F)ˣ) :
    localReciprocityUnitCharacter (v.adicCompletion F) p
        (finitePlaceAbsoluteH1AdicRestriction F p v
          (Additive.ofMul (psi.comp (globalMaximalAbelianRestriction F)))) a =
      psi (maximalAbelianGlobalArtin F (IdeleGroup.finitePlaceIdeleClass v a))