Module

PicDualNumberDeformationClassSpec.lean

Nyll.JacobianVarieties.Picard.PicDualNumberDeformationClassSpec
4 declarations indexed from sourceView source ↗

Cech classes of dual-number deformations

The overlap unit and compatibility condition specify the Cech class of a rigidified deformation.

Imports7
Imported by21

Declarations

AlgebraicGeometry.RelPicard.dualNumberThickening

The morphism of base changed covers induced by the inclusion into dual numbers.

Source context 6 commands

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

universe u
noncomputable section
open CategoryTheory CategoryTheory.Limits Opposite AlgebraicGeometry NeronModelInfra
  AlgebraicGeometry.Scheme.TwoAffineOpenCover
namespace AlgebraicGeometry.RelPicard
section Thickening
variable {R : Type u} [CommRing R] (A : Type u) [CommRing A] [Algebra R A]
  {C : Scheme.{u}} (𝒱 : C.TwoAffineOpenCover) (c : C ⟶ Spec (.of R))
abbrev dualNumberThickening :
    HomOver (IsScalarTower.toAlgHom R A (DualNumber A)).toRingHom
      (𝒱.pullback c A) (pullback.snd c (specMap R A))
      (𝒱.pullback c (DualNumber A)) (pullback.snd c (specMap R (DualNumber A)))
AlgebraicGeometry.RelPicard.oneAddEpsMul

The overlap unit represented by one plus epsilon times the pulled back section.

Source context 6 commands

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

universe u
noncomputable section
open CategoryTheory CategoryTheory.Limits Opposite AlgebraicGeometry NeronModelInfra
  AlgebraicGeometry.Scheme.TwoAffineOpenCover
namespace AlgebraicGeometry.RelPicard
section Thickening
variable {R : Type u} [CommRing R] (A : Type u) [CommRing A] [Algebra R A]
  {C : Scheme.{u}} (𝒱 : C.TwoAffineOpenCover) (c : C ⟶ Spec (.of R))
def oneAddEpsMul (f : ((𝒱.pullback c A).cover (pullback.snd c (specMap R A))).A01) :
    ((𝒱.pullback c (DualNumber A)).cover (pullback.snd c (specMap R (DualNumber A)))).A01
AlgebraicGeometry.RelPicard.H1StructureSheaf

First Cech cohomology of the structure sheaf on the base changed cover.

Source context 8 commands

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

universe u
noncomputable section
open CategoryTheory CategoryTheory.Limits Opposite AlgebraicGeometry NeronModelInfra
  AlgebraicGeometry.Scheme.TwoAffineOpenCover
namespace AlgebraicGeometry.RelPicard
section Spec
variable {R : Type u} [CommRing R] {C : Scheme.{u}}
variable (c : C ⟶ Spec (.of R)) (ε : SchemeHomOver (𝟙 (Spec (.of R))) c)
variable (A : Type u) [CommRing A] [Algebra R A] (𝒱 : C.TwoAffineOpenCover)
abbrev H1StructureSheaf : Type u
AlgebraicGeometry.RelPicard.IsDeformationClassMap

Compatibility of a rigidified dual-number deformation with its Cech overlap class.

Source context 8 commands

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

universe u
noncomputable section
open CategoryTheory CategoryTheory.Limits Opposite AlgebraicGeometry NeronModelInfra
  AlgebraicGeometry.Scheme.TwoAffineOpenCover
namespace AlgebraicGeometry.RelPicard
section Spec
variable {R : Type u} [CommRing R] {C : Scheme.{u}}
variable (c : C ⟶ Spec (.of R)) (ε : SchemeHomOver (𝟙 (Spec (.of R))) c)
variable (A : Type u) [CommRing A] [Algebra R A] (𝒱 : C.TwoAffineOpenCover)
def IsDeformationClassMap (δ : RigKerDualNumber c ε A → H1StructureSheaf c A 𝒱) : Prop