Module

QuasicoherentImage.lean

Nyll.SchemeTheory.Modules.QuasicoherentImage
4 declarations indexed from sourceView source ↗

Quasicoherence of native image subsheaves

The identity-action equivalence transports the actual kernel and cokernel theorems for scheme modules to native sheaves. The native image is then the actual kernel of the actual cokernel projection.

Declarations

SheafOfModules.schemeEquivalence_preservesZeroMorphisms
Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory Limits AlgebraicGeometry
namespace SheafOfModules
instance schemeEquivalence_preservesZeroMorphisms (X : Scheme.{u}) :
    (Scheme.Modules.sheafOfModulesEquivalence X).functor.PreservesZeroMorphisms where
  map_zero _ _ := rfl
SheafOfModules.isQuasicoherent_kernel_native

Native categorical kernels of quasicoherent sheaves on schemes are quasicoherent.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory Limits AlgebraicGeometry
namespace SheafOfModules
theorem isQuasicoherent_kernel_native {X : Scheme.{u}}
    {M N : SheafOfModules.{u} X.ringCatSheaf}
    [M.IsQuasicoherent] [N.IsQuasicoherent] (f : M ⟶ N) :
    (kernel f).IsQuasicoherent
SheafOfModules.isQuasicoherent_cokernel_native

Native categorical cokernels of quasicoherent sheaves on schemes are quasicoherent.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory Limits AlgebraicGeometry
namespace SheafOfModules
theorem isQuasicoherent_cokernel_native {X : Scheme.{u}}
    {M N : SheafOfModules.{u} X.ringCatSheaf}
    [M.IsQuasicoherent] [N.IsQuasicoherent] (f : M ⟶ N) :
    (cokernel f).IsQuasicoherent
SheafOfModules.isQuasicoherent_imageSubmodule

The actual native image submodule of a map of quasicoherent sheaves is quasicoherent.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory Limits AlgebraicGeometry
namespace SheafOfModules
theorem isQuasicoherent_imageSubmodule {X : Scheme.{u}}
    {M N : SheafOfModules.{u} X.ringCatSheaf}
    [M.IsQuasicoherent] [N.IsQuasicoherent] (f : M ⟶ N) :
    (imageSubmodule f).toSheafOfModules.IsQuasicoherent