Module

QuasicoherentPushforward.lean

Nyll.SchemeTheory.Modules.QuasicoherentPushforward
3 declarations indexed from sourceView source ↗

Quasicoherent direct images for open and affine morphisms

The affine-target theorem is transported from the actual Spec theorem through isoSpec. The arbitrary-target theorem uses the actual open-restriction comparison on each affine target open, then the native affine-cover criterion.

Imports12
Imported by3

Declarations

AlgebraicGeometry.Scheme.Modules.isQuasicoherent_pushforward_of_qcqs_toAffine

The direct image of a quasicoherent module from a quasi-compact, quasi-separated source to an affine target is quasicoherent.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace
namespace AlgebraicGeometry.Scheme.Modules
theorem isQuasicoherent_pushforward_of_qcqs_toAffine
    {X Y : Scheme.{u}} [IsAffine Y] (j : X ⟶ Y)
    [CompactSpace X] [QuasiSeparatedSpace X] (M : X.Modules) [M.IsQuasicoherent] :
    ((pushforward j).obj M).IsQuasicoherent
AlgebraicGeometry.Scheme.Modules.isQuasicoherent_pushforward_of_quasiCompact_openImmersion

The actual direct image of a quasicoherent module under a quasi-compact open immersion is quasicoherent over an arbitrary target scheme.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace
namespace AlgebraicGeometry.Scheme.Modules
theorem isQuasicoherent_pushforward_of_quasiCompact_openImmersion
    {X Y : Scheme.{u}} (j : X ⟶ Y) [IsOpenImmersion j] [QuasiCompact j]
    (M : X.Modules) [M.IsQuasicoherent] :
    ((pushforward j).obj M).IsQuasicoherent
AlgebraicGeometry.Scheme.Modules.isQuasicoherent_pushforward_of_isAffineHom

The actual direct image of a quasicoherent module along an affine morphism is quasicoherent, over an arbitrary target scheme.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace
namespace AlgebraicGeometry.Scheme.Modules
theorem isQuasicoherent_pushforward_of_isAffineHom
    {X Y : Scheme.{u}} (g : X ⟶ Y) [IsAffineHom g]
    (M : X.Modules) [M.IsQuasicoherent] :
    ((pushforward g).obj M).IsQuasicoherent