Module

AbelianMultiplicationMonodromyGroup.lean

Nyll.EtaleFundamentalGroups.GeometricFiber.AbelianMultiplicationMonodromyGroup
8 declarations indexed from sourceView source ↗

Additivity of actual multiplication monodromy

The torsion comparison preserves the underlying scheme point. Translation by that same point therefore acts on the actual geometric fibre by torsion addition. Naturality of a fibre-functor automorphism against these deck translations makes its action translation by its value at the unit. Thus unit evaluation sends the fundamental-group product to actual torsion addition.

Declarations

GoodReductionJacobian.RelativeGroupLaw.scalarIdentity_specMap
Source context 7 commands

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

noncomputable section
open CategoryTheory CategoryTheory.PreGaloisCategory AlgebraicGeometry NeronModelInfra
open AlgebraicCurves.Geometry.AbelianSchemes.Theorems.Proofs
open RelativeGroupLaw_schemeNsmul_comp_eq_comp_schemeNsmul_of_hom.S17Glue
namespace GoodReductionJacobian.RelativeGroupLaw
variable {K : Type} [Field K] {A : Scheme.{0}} {f : A ⟶ Spec (CommRingCat.of K)}
variable (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
theorem scalarIdentity_specMap :
    Spec.map (CommRingCat.ofHom (algebraMap K K)) = 𝟙 (Spec (CommRingCat.of K))
GoodReductionJacobian.RelativeGroupLaw.torsionPointSection

The actual torsion point, with the identity spectrum map as base.

Source context 7 commands

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

noncomputable section
open CategoryTheory CategoryTheory.PreGaloisCategory AlgebraicGeometry NeronModelInfra
open AlgebraicCurves.Geometry.AbelianSchemes.Theorems.Proofs
open RelativeGroupLaw_schemeNsmul_comp_eq_comp_schemeNsmul_of_hom.S17Glue
namespace GoodReductionJacobian.RelativeGroupLaw
variable {K : Type} [Field K] {A : Scheme.{0}} {f : A ⟶ Spec (CommRingCat.of K)}
variable (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
def torsionPointSection (n : ℕ+)
    (t : ProCGroups.torsionLevel (G.AlgPoints hc K) n) :
    SchemeHomOver (𝟙 (Spec (CommRingCat.of K))) f
GoodReductionJacobian.RelativeGroupLaw.torsionPointSection_isTorsion

The section underlying an algebraic torsion point is annihilated by the same multiplication map.

Source context 7 commands

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

noncomputable section
open CategoryTheory CategoryTheory.PreGaloisCategory AlgebraicGeometry NeronModelInfra
open AlgebraicCurves.Geometry.AbelianSchemes.Theorems.Proofs
open RelativeGroupLaw_schemeNsmul_comp_eq_comp_schemeNsmul_of_hom.S17Glue
namespace GoodReductionJacobian.RelativeGroupLaw
variable {K : Type} [Field K] {A : Scheme.{0}} {f : A ⟶ Spec (CommRingCat.of K)}
variable (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
theorem torsionPointSection_isTorsion (n : ℕ+)
    (t : ProCGroups.torsionLevel (G.AlgPoints hc K) n) :
    G.IsTorsionPoint (𝟙 (Spec (CommRingCat.of K))) (n : ℕ)
      (torsionPointSection G hc n t)
GoodReductionJacobian.RelativeGroupLaw.torsionDeckTranslation

The deck translation of the multiplication cover defined by an actual torsion point.

Source context 7 commands

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

noncomputable section
open CategoryTheory CategoryTheory.PreGaloisCategory AlgebraicGeometry NeronModelInfra
open AlgebraicCurves.Geometry.AbelianSchemes.Theorems.Proofs
open RelativeGroupLaw_schemeNsmul_comp_eq_comp_schemeNsmul_of_hom.S17Glue
namespace GoodReductionJacobian.RelativeGroupLaw
variable {K : Type} [Field K] {A : Scheme.{0}} {f : A ⟶ Spec (CommRingCat.of K)}
variable (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
def torsionDeckTranslation [CharZero K] [IsProper f] [Smooth f] (n : ℕ+)
    (t : ProCGroups.torsionLevel (G.AlgPoints hc K) n) :
    Aut (G.multiplicationCover hc n)
GoodReductionJacobian.RelativeGroupLaw.fiberEquiv_map_torsionDeckTranslation

The torsion-fibre comparison carries the actual deck translation to addition by its defining point.

Source context 8 commands

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

noncomputable section
open CategoryTheory CategoryTheory.PreGaloisCategory AlgebraicGeometry NeronModelInfra
open AlgebraicCurves.Geometry.AbelianSchemes.Theorems.Proofs
open RelativeGroupLaw_schemeNsmul_comp_eq_comp_schemeNsmul_of_hom.S17Glue
namespace GoodReductionJacobian.RelativeGroupLaw
variable {K : Type} [Field K] {A : Scheme.{0}} {f : A ⟶ Spec (CommRingCat.of K)}
variable (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
variable [IsAlgClosed K] [CharZero K] [IsProper f] [Smooth f]
theorem fiberEquiv_map_torsionDeckTranslation (n : ℕ+)
    (t : ProCGroups.torsionLevel (G.AlgPoints hc K) n)
    (z : (FiniteEtale.fiber (G.one (𝟙 (Spec (CommRingCat.of K)))).1).obj
      (G.multiplicationCover hc n)) :
    G.multiplicationCoverFiberEquivTorsion hc n
        ((FiniteEtale.fiber (G.one (𝟙 (Spec (CommRingCat.of K)))).1).map
          (torsionDeckTranslation G hc n t).hom z) =
      G.multiplicationCoverFiberEquivTorsion hc n z + t
GoodReductionJacobian.RelativeGroupLaw.multiplicationCoverFiberEquivTorsion_smul

Actual monodromy on every point of a multiplication fibre is addition by its value at the unit, under the actual torsion comparison.

Source context 8 commands

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

noncomputable section
open CategoryTheory CategoryTheory.PreGaloisCategory AlgebraicGeometry NeronModelInfra
open AlgebraicCurves.Geometry.AbelianSchemes.Theorems.Proofs
open RelativeGroupLaw_schemeNsmul_comp_eq_comp_schemeNsmul_of_hom.S17Glue
namespace GoodReductionJacobian.RelativeGroupLaw
variable {K : Type} [Field K] {A : Scheme.{0}} {f : A ⟶ Spec (CommRingCat.of K)}
variable (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
variable [IsAlgClosed K] [CharZero K] [IsProper f] [Smooth f]
theorem multiplicationCoverFiberEquivTorsion_smul (n : ℕ+)
    (g : π₁ᵉᵗ((G.one (𝟙 (Spec (CommRingCat.of K)))).1))
    (z : (FiniteEtale.fiber (G.one (𝟙 (Spec (CommRingCat.of K)))).1).obj
      (G.multiplicationCover hc n)) :
    G.multiplicationCoverFiberEquivTorsion hc n (g • z) =
      G.multiplicationMonodromy hc n g + G.multiplicationCoverFiberEquivTorsion hc n z
GoodReductionJacobian.RelativeGroupLaw.multiplicationMonodromy_one

Unit evaluation sends the identity of the actual fundamental group to zero.

Source context 8 commands

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

noncomputable section
open CategoryTheory CategoryTheory.PreGaloisCategory AlgebraicGeometry NeronModelInfra
open AlgebraicCurves.Geometry.AbelianSchemes.Theorems.Proofs
open RelativeGroupLaw_schemeNsmul_comp_eq_comp_schemeNsmul_of_hom.S17Glue
namespace GoodReductionJacobian.RelativeGroupLaw
variable {K : Type} [Field K] {A : Scheme.{0}} {f : A ⟶ Spec (CommRingCat.of K)}
variable (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
variable [IsAlgClosed K] [CharZero K] [IsProper f] [Smooth f]
theorem multiplicationMonodromy_one (n : ℕ+) :
    G.multiplicationMonodromy hc n 1 = 0
GoodReductionJacobian.RelativeGroupLaw.multiplicationMonodromy_mul

Unit evaluation sends the actual fundamental-group product to addition in the actual torsion subgroup of algebraic points.

Source context 8 commands

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

noncomputable section
open CategoryTheory CategoryTheory.PreGaloisCategory AlgebraicGeometry NeronModelInfra
open AlgebraicCurves.Geometry.AbelianSchemes.Theorems.Proofs
open RelativeGroupLaw_schemeNsmul_comp_eq_comp_schemeNsmul_of_hom.S17Glue
namespace GoodReductionJacobian.RelativeGroupLaw
variable {K : Type} [Field K] {A : Scheme.{0}} {f : A ⟶ Spec (CommRingCat.of K)}
variable (G : RelativeGroupLaw K f) (hc : G.IsCommutative)
variable [IsAlgClosed K] [CharZero K] [IsProper f] [Smooth f]
theorem multiplicationMonodromy_mul (n : ℕ+)
    (g h : π₁ᵉᵗ((G.one (𝟙 (Spec (CommRingCat.of K)))).1)) :
    G.multiplicationMonodromy hc n (g * h) =
      G.multiplicationMonodromy hc n g + G.multiplicationMonodromy hc n h