Module

GlobalSectionLocalization.lean

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

Localization from global sections

Transports the section-localization results through the existing global coefficient modules.

Imports12
Imported by2

Declarations

AlgebraicGeometry.Scheme.Modules.globalModulePresheaf

The existing native global-section module presheaf, evaluated once at its ringed-site owner.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules
def globalModulePresheaf {X : Scheme.{u}} (M : X.Modules) :
    X.Opensᵒᵖ ⥤ ModuleCat.{u} Γ(X, ⊤)
AlgebraicGeometry.Scheme.Modules.topMap_id
Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules
lemma topMap_id {X : Scheme.{u}} :
    (X.presheaf.map (⊤ : X.Opens).leTop.op).hom = RingHom.id Γ(X, ⊤)
AlgebraicGeometry.Scheme.Modules.nativeTopIso
Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules
def nativeTopIso {X : Scheme.{u}} (M : X.Modules) :
    (globalModulePresheaf M).obj (op ⊤) ≅ ModuleCat.of Γ(X, ⊤) Γ(M, ⊤)
AlgebraicGeometry.Scheme.Modules.nativeRestriction
Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules
abbrev nativeRestriction {X : Scheme.{u}} (M : X.Modules) (W : X.Opens) :
    ModuleCat.of Γ(X, ⊤) Γ(M, ⊤) ⟶ (globalModulePresheaf M).obj (op W)
AlgebraicGeometry.Scheme.Modules.restriction_comparison
Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules
theorem restriction_comparison {X : Scheme.{u}} (M : X.Modules) (W : X.Opens) :
    (globalModulePresheaf M).map W.leTop.op = (nativeTopIso M).hom ≫ nativeRestriction M W
AlgebraicGeometry.Scheme.Modules.nativeRestriction_isLocalized
Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules
lemma nativeRestriction_isLocalized {X : Scheme.{u}} (M : X.Modules)
    [M.IsQuasicoherent] [CompactSpace X] [QuasiSeparatedSpace X] (g : Γ(X, ⊤)) :
    IsLocalizedModule (Submonoid.powers g) (nativeRestriction M (X.basicOpen g)).hom
AlgebraicGeometry.Scheme.Modules.isLocalizedModule_forgetToModuleCat_of_qcqs

The native global-section module presheaf sends a basic-open restriction of a quasicoherent module on a qcqs scheme to actual localization.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules
theorem isLocalizedModule_forgetToModuleCat_of_qcqs {X : Scheme.{u}} (M : X.Modules)
    [M.IsQuasicoherent] [CompactSpace X] [QuasiSeparatedSpace X] (g : Γ(X, ⊤)) :
    IsLocalizedModule (Submonoid.powers g)
      ((globalModulePresheaf M).map (X.basicOpen g).leTop.op).hom
AlgebraicGeometry.Scheme.Modules.isLocalizedModule_restrictGlobalScalars_of_qcqs

The same genuine localization persists under the native restriction of coefficients along a prescribed ring homomorphism.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules
theorem isLocalizedModule_restrictGlobalScalars_of_qcqs {R : CommRingCat.{u}}
    {X : Scheme.{u}} (M : X.Modules) [M.IsQuasicoherent]
    [CompactSpace X] [QuasiSeparatedSpace X] (σ : R →+* Γ(X, ⊤)) (r : R) :
    IsLocalizedModule (Submonoid.powers r)
      ((globalModulePresheaf M ⋙
            ModuleCat.restrictScalars σ).map (X.basicOpen (σ r)).leTop.op).hom