Module

RepresentsRelSubPic_flat_mul_fst_snd.lean

Nyll.JacobianVarieties.Picard.RepresentsRelSubPic_flat_mul_fst_snd
5 declarations indexed from sourceView source ↗

Flatness of relative Picard multiplication

Multiplication on two points factors through an automorphism of the fibre product and its second projection. This proves flatness from the flat structure morphism.

Declarations

JacobianVarieties.Picard.Proofs.FlatMultiplication.AlgebraicGeometry.RelPicard.GrpMulFlat.mul_inv_cancel'
Source context 16 commands

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

section ProofImplementation
namespace JacobianVarieties.Picard.Proofs.FlatMultiplication
open _root_.CategoryTheory
open _root_.CategoryTheory.Limits
open _root_.AlgebraicGeometry
open _root_.NeronModelInfra
open _root_.GoodReductionJacobian
open _root_.AlgebraicGeometry.RelPicard
universe u
namespace AlgebraicGeometry
namespace RelPicard
namespace GrpMulFlat
open _root_.AlgebraicGeometry.RelPicard
open _root_.AlgebraicGeometry
variable {R : Type u} [CommRing R] {A : Scheme.{u}} {f : A ⟶ Spec (CommRingCat.of R)}
  (G : RelativeGroupLaw R f) (hc : G.IsCommutative)
include hc in
theorem mul_inv_cancel' {T : Scheme.{u}} (t : T ⟶ Spec (CommRingCat.of R)) (x : SchemeHomOver t f) :
    G.mul t x (G.inv t x) = G.one t
JacobianVarieties.Picard.Proofs.FlatMultiplication.AlgebraicGeometry.RelPicard.GrpMulFlat.inv_unique
Source context 16 commands

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

section ProofImplementation
namespace JacobianVarieties.Picard.Proofs.FlatMultiplication
open _root_.CategoryTheory
open _root_.CategoryTheory.Limits
open _root_.AlgebraicGeometry
open _root_.NeronModelInfra
open _root_.GoodReductionJacobian
open _root_.AlgebraicGeometry.RelPicard
universe u
namespace AlgebraicGeometry
namespace RelPicard
namespace GrpMulFlat
open _root_.AlgebraicGeometry.RelPicard
open _root_.AlgebraicGeometry
variable {R : Type u} [CommRing R] {A : Scheme.{u}} {f : A ⟶ Spec (CommRingCat.of R)}
  (G : RelativeGroupLaw R f) (hc : G.IsCommutative)
include hc in
theorem inv_unique {T : Scheme.{u}} (t : T ⟶ Spec (CommRingCat.of R)) (x y : SchemeHomOver t f)
    (hy : G.mul t y x = G.one t) : y = G.inv t x
JacobianVarieties.Picard.Proofs.FlatMultiplication.AlgebraicGeometry.RelPicard.GrpMulFlat.one_natural
Source context 15 commands

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

section ProofImplementation
namespace JacobianVarieties.Picard.Proofs.FlatMultiplication
open _root_.CategoryTheory
open _root_.CategoryTheory.Limits
open _root_.AlgebraicGeometry
open _root_.NeronModelInfra
open _root_.GoodReductionJacobian
open _root_.AlgebraicGeometry.RelPicard
universe u
namespace AlgebraicGeometry
namespace RelPicard
namespace GrpMulFlat
open _root_.AlgebraicGeometry.RelPicard
open _root_.AlgebraicGeometry
variable {R : Type u} [CommRing R] {A : Scheme.{u}} {f : A ⟶ Spec (CommRingCat.of R)}
  (G : RelativeGroupLaw R f) (hc : G.IsCommutative)
theorem one_natural {T T' : Scheme.{u}} (t : T ⟶ Spec (CommRingCat.of R))
    (t' : T' ⟶ Spec (CommRingCat.of R))
    (ψ : T' ⟶ T) (hψ : ψ ≫ t = t') :
    GoodReductionJacobian.schemeHomOverComp ψ hψ (G.one t) = G.one t'
JacobianVarieties.Picard.Proofs.FlatMultiplication.AlgebraicGeometry.RelPicard.GrpMulFlat.inv_natural
Source context 16 commands

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

section ProofImplementation
namespace JacobianVarieties.Picard.Proofs.FlatMultiplication
open _root_.CategoryTheory
open _root_.CategoryTheory.Limits
open _root_.AlgebraicGeometry
open _root_.NeronModelInfra
open _root_.GoodReductionJacobian
open _root_.AlgebraicGeometry.RelPicard
universe u
namespace AlgebraicGeometry
namespace RelPicard
namespace GrpMulFlat
open _root_.AlgebraicGeometry.RelPicard
open _root_.AlgebraicGeometry
variable {R : Type u} [CommRing R] {A : Scheme.{u}} {f : A ⟶ Spec (CommRingCat.of R)}
  (G : RelativeGroupLaw R f) (hc : G.IsCommutative)
include hc in
theorem inv_natural {T T' : Scheme.{u}} (t : T ⟶ Spec (CommRingCat.of R))
    (t' : T' ⟶ Spec (CommRingCat.of R))
    (ψ : T' ⟶ T) (hψ : ψ ≫ t = t') (x : SchemeHomOver t f) :
    GoodReductionJacobian.schemeHomOverComp ψ hψ (G.inv t x) =
      G.inv t' (GoodReductionJacobian.schemeHomOverComp ψ hψ x)
AlgebraicGeometry.RelPicard.RepresentsRelSubPic.flat_mul_fst_snd
Source context 10 commands

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

section ProofImplementation
namespace JacobianVarieties.Picard.Proofs.FlatMultiplication
open _root_.CategoryTheory
open _root_.CategoryTheory.Limits
open _root_.AlgebraicGeometry
open _root_.NeronModelInfra
open _root_.GoodReductionJacobian
open _root_.AlgebraicGeometry.RelPicard
universe u
open AlgebraicGeometry.RelPicard.GrpMulFlat in
theorem _root_.AlgebraicGeometry.RelPicard.RepresentsRelSubPic.flat_mul_fst_snd
    {R : Type u} [CommRing R] {C : Scheme.{u}} {c : C ⟶ Spec (CommRingCat.of R)}
    {ε : SchemeHomOver (𝟙 (Spec (CommRingCat.of R))) c}
    {P : SubPicGroupCondition c ε} {D : RelativePic0Designation R c}
    (h : RepresentsRelSubPic c ε P.toSubPicCondition D) [Flat D.toBase] :
    Flat (h.relativeGroupLaw.mul (pullback.fst D.toBase D.toBase ≫ D.toBase)
      ⟨pullback.fst D.toBase D.toBase, rfl⟩
      ⟨pullback.snd D.toBase D.toBase, pullback.condition.symm⟩).1