Module

AbelianPrimeToTateComparison.lean

Nyll.EtaleFundamentalGroups.GeometricFiber.AbelianPrimeToTateComparison
9 declarations indexed from sourceView source ↗

The actual prime-to-p fundamental group and Tate module

The kernel of all invertible multiplication coordinates is the actual residual core for finite groups of order prime to the characteristic. One inclusion uses the actual finite torsion groups and Cauchy's theorem. The other uses the actual image of the multiplication-cover fundamental group and powers in finite Sigma quotients. No p-primary part is discarded by hypothesis.

Declarations

GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication.sigmaNumber_of_unitIndex
Source context 7 commands

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

noncomputable section
open CategoryTheory AlgebraicGeometry AlgebraicGeometry.FiniteEtale
open ProCGroups ProCGroups.ProC
namespace GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication
variable {K : Type} [Field K]
section Indices
variable (p : ℕ) [CharP K p]
theorem sigmaNumber_of_unitIndex (n : unitIndices K) :
    FiniteGroupClass.IsSigmaNumber ({p}ᶜ : Set ℕ) (n.1 : ℕ)
GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication.mem_unitIndices_iff_coprime

The invertible positive indices are precisely those prime to the characteristic.

Source context 8 commands

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

noncomputable section
open CategoryTheory AlgebraicGeometry AlgebraicGeometry.FiniteEtale
open ProCGroups ProCGroups.ProC
namespace GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication
variable {K : Type} [Field K]
section Indices
variable (p : ℕ) [CharP K p]
variable [Fact p.Prime]
theorem mem_unitIndices_iff_coprime (n : ℕ+) :
    n ∈ unitIndices K ↔ (n : ℕ).Coprime p
GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication.isUnit_of_sigmaNumber
Source context 8 commands

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

noncomputable section
open CategoryTheory AlgebraicGeometry AlgebraicGeometry.FiniteEtale
open ProCGroups ProCGroups.ProC
namespace GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication
variable {K : Type} [Field K]
section Indices
variable (p : ℕ) [CharP K p]
variable [Fact p.Prime]
theorem isUnit_of_sigmaNumber (n : ℕ)
    (hn : FiniteGroupClass.IsSigmaNumber ({p}ᶜ : Set ℕ) n) : IsUnit (n : K)
Source context 6 commands

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

noncomputable section
open CategoryTheory AlgebraicGeometry AlgebraicGeometry.FiniteEtale
open ProCGroups ProCGroups.ProC
namespace GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication
variable {K : Type} [Field K]
variable [IsSepClosed K] {A : Scheme} {f : A ⟶ Spec (.of K)}
  [IsProper f] [Smooth f] [GeometricallyConnected f]
  (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
  (p : ℕ) [Fact p.Prime] [CharP K p]
instance (n : ℕ+) : TopologicalSpace (torsionLevel (G.AlgPoints hc K) n)
Source context 7 commands

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

noncomputable section
open CategoryTheory AlgebraicGeometry AlgebraicGeometry.FiniteEtale
open ProCGroups ProCGroups.ProC
namespace GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication
variable {K : Type} [Field K]
variable [IsSepClosed K] {A : Scheme} {f : A ⟶ Spec (.of K)}
  [IsProper f] [Smooth f] [GeometricallyConnected f]
  (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
  (p : ℕ) [Fact p.Prime] [CharP K p]
local instance (n : ℕ+) : TopologicalSpace (torsionLevel (G.AlgPoints hc K) n) :=
  FullTateModule.torsionLevelTopology (G.AlgPoints hc K) n
instance (n : ℕ+) : DiscreteTopology (torsionLevel (G.AlgPoints hc K) n)
GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication.toTateHom_ker_eq_residualCore

The kernel of the actual compatible-family map is precisely the actual prime-to-p residual core of the original fundamental group.

Source context 8 commands

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

noncomputable section
open CategoryTheory AlgebraicGeometry AlgebraicGeometry.FiniteEtale
open ProCGroups ProCGroups.ProC
namespace GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication
variable {K : Type} [Field K]
variable [IsSepClosed K] {A : Scheme} {f : A ⟶ Spec (.of K)}
  [IsProper f] [Smooth f] [GeometricallyConnected f]
  (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
  (p : ℕ) [Fact p.Prime] [CharP K p]
local instance (n : ℕ+) : TopologicalSpace (torsionLevel (G.AlgPoints hc K) n) :=
  FullTateModule.torsionLevelTopology (G.AlgPoints hc K) n
local instance (n : ℕ+) : DiscreteTopology (torsionLevel (G.AlgPoints hc K) n) := ⟨rfl⟩
theorem toTateHom_ker_eq_residualCore :
    (toTateHom G hc).toMonoidHom.ker =
      proCResidualCore (FiniteGroupClass.sigmaGroup ({p}ᶜ : Set ℕ))
        π₁ᵉᵗ((G.one (𝟙 (Spec (.of K)))).1)
GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication.fundamentalGroupPrimeToEquivTate

The maximal prime-to-p quotient of the actual etale fundamental group is the inverse limit of the actual torsion points at all prime-to-p indices.

Source context 8 commands

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

noncomputable section
open CategoryTheory AlgebraicGeometry AlgebraicGeometry.FiniteEtale
open ProCGroups ProCGroups.ProC
namespace GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication
variable {K : Type} [Field K]
variable [IsSepClosed K] {A : Scheme} {f : A ⟶ Spec (.of K)}
  [IsProper f] [Smooth f] [GeometricallyConnected f]
  (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
  (p : ℕ) [Fact p.Prime] [CharP K p]
local instance (n : ℕ+) : TopologicalSpace (torsionLevel (G.AlgPoints hc K) n) :=
  FullTateModule.torsionLevelTopology (G.AlgPoints hc K) n
local instance (n : ℕ+) : DiscreteTopology (torsionLevel (G.AlgPoints hc K) n) := ⟨rfl⟩
def fundamentalGroupPrimeToEquivTate :
    (π₁ᵉᵗ((G.one (𝟙 (Spec (.of K)))).1) ⧸
      proCResidualCore (FiniteGroupClass.sigmaGroup ({p}ᶜ : Set ℕ))
        π₁ᵉᵗ((G.one (𝟙 (Spec (.of K)))).1)) ≃ₜ*
      Multiplicative (RestrictedTateModule (G.AlgPoints hc K) (unitIndices K))
GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication.fundamentalGroupPrimeToEquivTate_projection

Every coordinate is the action on the actual unit of the actual multiplication fibre.

Source context 8 commands

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

noncomputable section
open CategoryTheory AlgebraicGeometry AlgebraicGeometry.FiniteEtale
open ProCGroups ProCGroups.ProC
namespace GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication
variable {K : Type} [Field K]
variable [IsSepClosed K] {A : Scheme} {f : A ⟶ Spec (.of K)}
  [IsProper f] [Smooth f] [GeometricallyConnected f]
  (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
  (p : ℕ) [Fact p.Prime] [CharP K p]
local instance (n : ℕ+) : TopologicalSpace (torsionLevel (G.AlgPoints hc K) n) :=
  FullTateModule.torsionLevelTopology (G.AlgPoints hc K) n
local instance (n : ℕ+) : DiscreteTopology (torsionLevel (G.AlgPoints hc K) n) := ⟨rfl⟩
theorem fundamentalGroupPrimeToEquivTate_projection
    (g : π₁ᵉᵗ((G.one (𝟙 (Spec (.of K)))).1)) (n : unitIndices K) :
    RestrictedTateModule.projection (G.AlgPoints hc K) (unitIndices K) n
      (Multiplicative.toAdd (fundamentalGroupPrimeToEquivTate G hc p
        (QuotientGroup.mk'
          (proCResidualCore (FiniteGroupClass.sigmaGroup ({p}ᶜ : Set ℕ))
            π₁ᵉᵗ((G.one (𝟙 (Spec (.of K)))).1)) g))) = monodromy G hc n g
GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication.fundamentalGroupPrimeToEquivTateAt

At any separably closed geometric basepoint, the same actual prime-to-p Tate module describes the maximal prime-to-p quotient. The basepoint comparison is chosen internally from the actual fibre-functor comparison theorem.

Source context 8 commands

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

noncomputable section
open CategoryTheory AlgebraicGeometry AlgebraicGeometry.FiniteEtale
open ProCGroups ProCGroups.ProC
namespace GoodReductionJacobian.RelativeGroupLaw.UnitMultiplication
variable {K : Type} [Field K]
variable [IsSepClosed K] {A : Scheme} {f : A ⟶ Spec (.of K)}
  [IsProper f] [Smooth f] [GeometricallyConnected f]
  (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
  (p : ℕ) [Fact p.Prime] [CharP K p]
local instance (n : ℕ+) : TopologicalSpace (torsionLevel (G.AlgPoints hc K) n) :=
  FullTateModule.torsionLevelTopology (G.AlgPoints hc K) n
local instance (n : ℕ+) : DiscreteTopology (torsionLevel (G.AlgPoints hc K) n) := ⟨rfl⟩
def fundamentalGroupPrimeToEquivTateAt
    {Ω : Type} [Field Ω] [IsSepClosed Ω] (xi : Spec (.of Ω) ⟶ A) :
    (π₁ᵉᵗ(xi) ⧸ proCResidualCore (FiniteGroupClass.sigmaGroup ({p}ᶜ : Set ℕ)) π₁ᵉᵗ(xi)) ≃ₜ*
      Multiplicative (RestrictedTateModule (G.AlgPoints hc K) (unitIndices K))