Module

Invertible.lean

Nyll.SchemeTheory.Modules.Invertible
5 declarations indexed from sourceView source ↗

Invertible scheme modules and the canonical pullback of the unit module.

Declarations

AlgebraicGeometry.Scheme.Modules.IsInvertible

A sheaf of modules locally isomorphic to the unit module around every point.

Source context 4 commands

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

universe u
open CategoryTheory CategoryTheory.Limits
noncomputable section
namespace AlgebraicGeometry
structure Scheme.Modules.IsInvertible {X : Scheme.{u}} (M : X.Modules) : Prop where
  /-- Every point has an open neighborhood on which the module is trivial. -/
  exists_trivialization : ∀ x : X, ∃ (U : X.Opens), x ∈ U ∧
    Nonempty ((Scheme.Modules.pullback U.ι).obj M ≅ SheafOfModules.unit U.toScheme.ringCatSheaf)
AlgebraicGeometry.Scheme.Hom.opensMapFinal
Source context 4 commands

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

universe u
open CategoryTheory CategoryTheory.Limits
noncomputable section
namespace AlgebraicGeometry
instance Scheme.Hom.opensMapFinal {X Y : Scheme.{u}} (f : X ⟶ Y) :
    (TopologicalSpace.Opens.map f.base).Final
AlgebraicGeometry.Scheme.Modules.pullbackUnitIso

The canonical identification of the pullback of the unit module with the unit module.

Source context 4 commands

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

universe u
open CategoryTheory CategoryTheory.Limits
noncomputable section
namespace AlgebraicGeometry
def Scheme.Modules.pullbackUnitIso {X Y : Scheme.{u}} (f : X ⟶ Y) :
    (Scheme.Modules.pullback f).obj (SheafOfModules.unit Y.ringCatSheaf) ≅
      SheafOfModules.unit X.ringCatSheaf
AlgebraicGeometry.Scheme.Modules.isInvertible_unit
Source context 4 commands

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

universe u
open CategoryTheory CategoryTheory.Limits
noncomputable section
namespace AlgebraicGeometry
theorem Scheme.Modules.isInvertible_unit (X : Scheme.{u}) :
    Scheme.Modules.IsInvertible (SheafOfModules.unit X.ringCatSheaf)
AlgebraicGeometry.Scheme.Modules.IsInvertible.pullback
Source context 4 commands

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

universe u
open CategoryTheory CategoryTheory.Limits
noncomputable section
namespace AlgebraicGeometry
theorem Scheme.Modules.IsInvertible.pullback {X Y : Scheme.{u}} (f : X ⟶ Y) {L : Y.Modules}
    (hL : Scheme.Modules.IsInvertible L) :
    Scheme.Modules.IsInvertible ((Scheme.Modules.pullback f).obj L)