Module

PolarisationRosati.lean

Nyll.AlgebraicCurves.Geometry.Picard.PolarisationRosati
12 declarations indexed from sourceView source ↗

Polarisation Rosati

Imports2
Imported by26

Declarations

AlgebraicGeometry.Polarisation.idPt

The identity morphism regarded as a point of the scheme over its base.

Source context 5 commands

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

noncomputable section
universe u v
open CategoryTheory CategoryTheory.Limits MonoidalCategory AlgebraicGeometry NeronModelInfra
  GoodReductionJacobian
namespace AlgebraicGeometry.Polarisation
variable {S : Type u} [CommRing S] {A : Scheme.{u}} (f : A ⟶ Spec (CommRingCat.of S)) (L :
  RelativeGroupLaw S f)
def idPt : SchemeHomOver f f
AlgebraicGeometry.Polarisation.negMor

The scheme morphism implementing inversion in the relative group law.

Source context 5 commands

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

noncomputable section
universe u v
open CategoryTheory CategoryTheory.Limits MonoidalCategory AlgebraicGeometry NeronModelInfra
  GoodReductionJacobian
namespace AlgebraicGeometry.Polarisation
variable {S : Type u} [CommRing S] {A : Scheme.{u}} (f : A ⟶ Spec (CommRingCat.of S)) (L :
  RelativeGroupLaw S f)
def negMor : A ⟶ A
AlgebraicGeometry.Polarisation.negMor_over
Source context 5 commands

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

noncomputable section
universe u v
open CategoryTheory CategoryTheory.Limits MonoidalCategory AlgebraicGeometry NeronModelInfra
  GoodReductionJacobian
namespace AlgebraicGeometry.Polarisation
variable {S : Type u} [CommRing S] {A : Scheme.{u}} (f : A ⟶ Spec (CommRingCat.of S)) (L :
  RelativeGroupLaw S f)
theorem negMor_over : negMor f L ≫ f = f
AlgebraicGeometry.Polarisation.addMor

The scheme morphism implementing multiplication in the relative group law.

Source context 5 commands

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

noncomputable section
universe u v
open CategoryTheory CategoryTheory.Limits MonoidalCategory AlgebraicGeometry NeronModelInfra
  GoodReductionJacobian
namespace AlgebraicGeometry.Polarisation
variable {S : Type u} [CommRing S] {A : Scheme.{u}} (f : A ⟶ Spec (CommRingCat.of S)) (L :
  RelativeGroupLaw S f)
def addMor : pullback f f ⟶ A
AlgebraicGeometry.Polarisation.addMor_over
Source context 5 commands

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

noncomputable section
universe u v
open CategoryTheory CategoryTheory.Limits MonoidalCategory AlgebraicGeometry NeronModelInfra
  GoodReductionJacobian
namespace AlgebraicGeometry.Polarisation
variable {S : Type u} [CommRing S] {A : Scheme.{u}} (f : A ⟶ Spec (CommRingCat.of S)) (L :
  RelativeGroupLaw S f)
theorem addMor_over : addMor f L ≫ f = pullback.fst f f ≫ f
AlgebraicGeometry.Polarisation.LocIsoOnBase

The module sheaves become isomorphic locally on the base spectrum.

Source context 5 commands

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

noncomputable section
universe u v
open CategoryTheory CategoryTheory.Limits MonoidalCategory AlgebraicGeometry NeronModelInfra
  GoodReductionJacobian
namespace AlgebraicGeometry.Polarisation
variable {S : Type u} [CommRing S] {A : Scheme.{u}} (f : A ⟶ Spec (CommRingCat.of S)) (L :
  RelativeGroupLaw S f)
def LocIsoOnBase {S' : Type u} [CommRing S'] {X : Scheme.{u}} (g : X ⟶ Spec (CommRingCat.of S')) (M
  M' : X.Modules) : Prop
AlgebraicGeometry.Polarisation.IsSymmetric

The module sheaf is locally isomorphic on the base to its pullback under inversion.

Source context 5 commands

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

noncomputable section
universe u v
open CategoryTheory CategoryTheory.Limits MonoidalCategory AlgebraicGeometry NeronModelInfra
  GoodReductionJacobian
namespace AlgebraicGeometry.Polarisation
variable {S : Type u} [CommRing S] {A : Scheme.{u}} (f : A ⟶ Spec (CommRingCat.of S)) (L :
  RelativeGroupLaw S f)
def IsSymmetric (𝓛 : A.Modules) : Prop
AlgebraicGeometry.Polarisation.mumfordBundle

The pullback under addition tensored with the duals pulled back from both factors.

Source context 5 commands

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

noncomputable section
universe u v
open CategoryTheory CategoryTheory.Limits MonoidalCategory AlgebraicGeometry NeronModelInfra
  GoodReductionJacobian
namespace AlgebraicGeometry.Polarisation
variable {S : Type u} [CommRing S] {A : Scheme.{u}} (f : A ⟶ Spec (CommRingCat.of S)) (L :
  RelativeGroupLaw S f)
def mumfordBundle (𝓛 : A.Modules) : (pullback f f).Modules
AlgebraicGeometry.Polarisation.sliceAt

The morphism into the square of the scheme defined by a point in the second factor.

Source context 5 commands

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

noncomputable section
universe u v
open CategoryTheory CategoryTheory.Limits MonoidalCategory AlgebraicGeometry NeronModelInfra
  GoodReductionJacobian
namespace AlgebraicGeometry.Polarisation
variable {S : Type u} [CommRing S] {A : Scheme.{u}} (f : A ⟶ Spec (CommRingCat.of S)) (L :
  RelativeGroupLaw S f)
def sliceAt {T : Scheme.{u}} {t : T ⟶ Spec (CommRingCat.of S)} (x : SchemeHomOver t f) :
    pullback f t ⟶ pullback f f
AlgebraicGeometry.Polarisation.KernelTrivial

Local triviality of the sliced Mumford bundle forces the point to be the identity.

Source context 5 commands

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

noncomputable section
universe u v
open CategoryTheory CategoryTheory.Limits MonoidalCategory AlgebraicGeometry NeronModelInfra
  GoodReductionJacobian
namespace AlgebraicGeometry.Polarisation
variable {S : Type u} [CommRing S] {A : Scheme.{u}} (f : A ⟶ Spec (CommRingCat.of S)) (L :
  RelativeGroupLaw S f)
def KernelTrivial (𝓛 : A.Modules) : Prop
AlgebraicGeometry.Polarisation.KernelIsTwoTorsion

Local triviality of the sliced Mumford bundle is equivalent to the point being two-torsion.

Source context 5 commands

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

noncomputable section
universe u v
open CategoryTheory CategoryTheory.Limits MonoidalCategory AlgebraicGeometry NeronModelInfra
  GoodReductionJacobian
namespace AlgebraicGeometry.Polarisation
variable {S : Type u} [CommRing S] {A : Scheme.{u}} (f : A ⟶ Spec (CommRingCat.of S)) (L :
  RelativeGroupLaw S f)
def KernelIsTwoTorsion (𝓛 : A.Modules) : Prop
AlgebraicGeometry.Polarisation.RosatiCompatible

The action and its adjoint give locally isomorphic pullbacks of the Mumford bundle.

Source context 5 commands

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

noncomputable section
universe u v
open CategoryTheory CategoryTheory.Limits MonoidalCategory AlgebraicGeometry NeronModelInfra
  GoodReductionJacobian
namespace AlgebraicGeometry.Polarisation
variable {S : Type u} [CommRing S] {A : Scheme.{u}} (f : A ⟶ Spec (CommRingCat.of S)) (L :
  RelativeGroupLaw S f)
def RosatiCompatible (𝓛 : A.Modules) {I : Type v} (ι : I → (A ⟶ A)) (hι : ∀ b, ι b ≫ f = f) (star :
  I → I) : Prop