Module

GeneratedAlgebraSource.lean

Nyll.SchemeTheory.Modules.GeneratedAlgebraSource
8 declarations indexed from sourceView source ↗

The original source maps to its generated relative algebra model

The inclusion of the actual generated section rings induces a map of the literal spectrum diagrams. The previously proved colimit with vertex the original affine-morphism source gives the scheme morphism. Its composite with the generated model's structure morphism is the original morphism. Consequently source surjectivity supplies surjectivity of the model.

Imports6
Imported by2

Declarations

AlgebraicGeometry.Scheme.DirectImageAlgebra.generatedDiagram_isLocallyDirected
Source context 8 commands

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

noncomputable section
universe u
open CategoryTheory Limits Opposite
namespace AlgebraicGeometry.Scheme.DirectImageAlgebra
variable {T X : Scheme.{u}} (g : T ⟶ X) [IsAffineHom g]
variable [(RelativeSpec.underlyingModule (structureMap g)).IsQuasicoherent]
variable (N : SheafOfModules.Submodule (RelativeSpec.underlyingModule (structureMap g)))
variable [(show X.Modules from N.toSheafOfModules).IsQuasicoherent]
instance generatedDiagram_isLocallyDirected :
    ((GeneratedAlgebra.gluingData (structureMap g) N).functor ⋙
      Scheme.forget).IsLocallyDirected
AlgebraicGeometry.Scheme.DirectImageAlgebra.generatedDiagramMap

The actual generated-ring inclusion, mapped contravariantly by Spec.

Source context 9 commands

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

noncomputable section
universe u
open CategoryTheory Limits Opposite
namespace AlgebraicGeometry.Scheme.DirectImageAlgebra
variable {T X : Scheme.{u}} (g : T ⟶ X) [IsAffineHom g]
variable [(RelativeSpec.underlyingModule (structureMap g)).IsQuasicoherent]
variable (N : SheafOfModules.Submodule (RelativeSpec.underlyingModule (structureMap g)))
variable [(show X.Modules from N.toSheafOfModules).IsQuasicoherent]
local instance generatedDiagram_isLocallyDirected :
    ((GeneratedAlgebra.gluingData (structureMap g) N).functor ⋙
      Scheme.forget).IsLocallyDirected :=
  Cover.RelativeGluingData.instIsLocallyDirectedI₀CompFunctorForgetOfIsThin
    (GeneratedAlgebra.gluingData (structureMap g) N)
def generatedDiagramMap :
    AffineSourceColimit.diagram g ⟶ (GeneratedAlgebra.gluingData (structureMap g) N).functor
AlgebraicGeometry.Scheme.DirectImageAlgebra.generatedCocone
Source context 9 commands

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

noncomputable section
universe u
open CategoryTheory Limits Opposite
namespace AlgebraicGeometry.Scheme.DirectImageAlgebra
variable {T X : Scheme.{u}} (g : T ⟶ X) [IsAffineHom g]
variable [(RelativeSpec.underlyingModule (structureMap g)).IsQuasicoherent]
variable (N : SheafOfModules.Submodule (RelativeSpec.underlyingModule (structureMap g)))
variable [(show X.Modules from N.toSheafOfModules).IsQuasicoherent]
local instance generatedDiagram_isLocallyDirected :
    ((GeneratedAlgebra.gluingData (structureMap g) N).functor ⋙
      Scheme.forget).IsLocallyDirected :=
  Cover.RelativeGluingData.instIsLocallyDirectedI₀CompFunctorForgetOfIsThin
    (GeneratedAlgebra.gluingData (structureMap g) N)
def generatedCocone : Cocone (AffineSourceColimit.diagram g) where
  pt := GeneratedAlgebra.scheme (structureMap g) N
  ι := generatedDiagramMap g N ≫
    (colimit.cocone (GeneratedAlgebra.gluingData (structureMap g) N).functor).ι
AlgebraicGeometry.Scheme.DirectImageAlgebra.toGenerated

The map from the original scheme source to the actual generated relative model, using the original source's proved colimit.

Source context 9 commands

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

noncomputable section
universe u
open CategoryTheory Limits Opposite
namespace AlgebraicGeometry.Scheme.DirectImageAlgebra
variable {T X : Scheme.{u}} (g : T ⟶ X) [IsAffineHom g]
variable [(RelativeSpec.underlyingModule (structureMap g)).IsQuasicoherent]
variable (N : SheafOfModules.Submodule (RelativeSpec.underlyingModule (structureMap g)))
variable [(show X.Modules from N.toSheafOfModules).IsQuasicoherent]
local instance generatedDiagram_isLocallyDirected :
    ((GeneratedAlgebra.gluingData (structureMap g) N).functor ⋙
      Scheme.forget).IsLocallyDirected :=
  Cover.RelativeGluingData.instIsLocallyDirectedI₀CompFunctorForgetOfIsThin
    (GeneratedAlgebra.gluingData (structureMap g) N)
def toGenerated : T ⟶ GeneratedAlgebra.scheme (structureMap g) N
AlgebraicGeometry.Scheme.DirectImageAlgebra.fromSpec_toGenerated

On a literal source affine chart, the new morphism is Spec of the actual inclusion of generated sections.

Source context 9 commands

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

noncomputable section
universe u
open CategoryTheory Limits Opposite
namespace AlgebraicGeometry.Scheme.DirectImageAlgebra
variable {T X : Scheme.{u}} (g : T ⟶ X) [IsAffineHom g]
variable [(RelativeSpec.underlyingModule (structureMap g)).IsQuasicoherent]
variable (N : SheafOfModules.Submodule (RelativeSpec.underlyingModule (structureMap g)))
variable [(show X.Modules from N.toSheafOfModules).IsQuasicoherent]
local instance generatedDiagram_isLocallyDirected :
    ((GeneratedAlgebra.gluingData (structureMap g) N).functor ⋙
      Scheme.forget).IsLocallyDirected :=
  Cover.RelativeGluingData.instIsLocallyDirectedI₀CompFunctorForgetOfIsThin
    (GeneratedAlgebra.gluingData (structureMap g) N)
theorem fromSpec_toGenerated (U : X.AffineZariskiSite) :
    (U.2.preimage g).fromSpec ≫ toGenerated g N =
      Spec.map ((GeneratedAlgebra.inclusion (structureMap g) N.toSubmodule).app (op U.1)) ≫
        colimit.ι (GeneratedAlgebra.gluingData (structureMap g) N).functor U
AlgebraicGeometry.Scheme.DirectImageAlgebra.generatedChart_toBase
Source context 10 commands

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

noncomputable section
universe u
open CategoryTheory Limits Opposite
namespace AlgebraicGeometry.Scheme.DirectImageAlgebra
variable {T X : Scheme.{u}} (g : T ⟶ X) [IsAffineHom g]
variable [(RelativeSpec.underlyingModule (structureMap g)).IsQuasicoherent]
variable (N : SheafOfModules.Submodule (RelativeSpec.underlyingModule (structureMap g)))
variable [(show X.Modules from N.toSheafOfModules).IsQuasicoherent]
local instance generatedDiagram_isLocallyDirected :
    ((GeneratedAlgebra.gluingData (structureMap g) N).functor ⋙
      Scheme.forget).IsLocallyDirected :=
  Cover.RelativeGluingData.instIsLocallyDirectedI₀CompFunctorForgetOfIsThin
    (GeneratedAlgebra.gluingData (structureMap g) N)
omit [IsAffineHom g] in
theorem generatedChart_toBase (U : X.AffineZariskiSite) :
    colimit.ι (GeneratedAlgebra.gluingData (structureMap g) N).functor U ≫
        GeneratedAlgebra.toBase (structureMap g) N =
      Spec.map ((GeneratedAlgebra.structureMap (structureMap g) N.toSubmodule).app (op U.1)) ≫
        U.2.fromSpec
AlgebraicGeometry.Scheme.DirectImageAlgebra.toGenerated_toBase

The actual original source morphism factors through the generated model.

Source context 9 commands

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

noncomputable section
universe u
open CategoryTheory Limits Opposite
namespace AlgebraicGeometry.Scheme.DirectImageAlgebra
variable {T X : Scheme.{u}} (g : T ⟶ X) [IsAffineHom g]
variable [(RelativeSpec.underlyingModule (structureMap g)).IsQuasicoherent]
variable (N : SheafOfModules.Submodule (RelativeSpec.underlyingModule (structureMap g)))
variable [(show X.Modules from N.toSheafOfModules).IsQuasicoherent]
local instance generatedDiagram_isLocallyDirected :
    ((GeneratedAlgebra.gluingData (structureMap g) N).functor ⋙
      Scheme.forget).IsLocallyDirected :=
  Cover.RelativeGluingData.instIsLocallyDirectedI₀CompFunctorForgetOfIsThin
    (GeneratedAlgebra.gluingData (structureMap g) N)
theorem toGenerated_toBase :
    toGenerated g N ≫ GeneratedAlgebra.toBase (structureMap g) N = g
AlgebraicGeometry.Scheme.DirectImageAlgebra.surjective_toBase

Surjectivity of the original morphism gives surjectivity of the actual generated model's structure map.

Source context 9 commands

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

noncomputable section
universe u
open CategoryTheory Limits Opposite
namespace AlgebraicGeometry.Scheme.DirectImageAlgebra
variable {T X : Scheme.{u}} (g : T ⟶ X) [IsAffineHom g]
variable [(RelativeSpec.underlyingModule (structureMap g)).IsQuasicoherent]
variable (N : SheafOfModules.Submodule (RelativeSpec.underlyingModule (structureMap g)))
variable [(show X.Modules from N.toSheafOfModules).IsQuasicoherent]
local instance generatedDiagram_isLocallyDirected :
    ((GeneratedAlgebra.gluingData (structureMap g) N).functor ⋙
      Scheme.forget).IsLocallyDirected :=
  Cover.RelativeGluingData.instIsLocallyDirectedI₀CompFunctorForgetOfIsThin
    (GeneratedAlgebra.gluingData (structureMap g) N)
theorem surjective_toBase [Surjective g] :
    Surjective (GeneratedAlgebra.toBase (structureMap g) N)