The adjunction tilde ⊣ Γ between modules over R and sheaves of modules
on Spec R.
Instances For
The tilde functor is fully faithful, the categorical input to the
equivalence Mod R ≃ QCoh(Spec R).
Instances For
For every R-module M, the sheaf M̃ on Spec R is quasi-coherent.
The unit of the tilde ⊣ Γ adjunction is an isomorphism (the affine
reconstruction Γ(M̃) ≅ M).
Equivalence of categories between Mod R and the essential image of the
tilde functor, packaging the fully-faithful corestriction.
Instances For
theorem
tilde_essImage_iff_isIso_counit
{R : CommRingCat}
(M : (AlgebraicGeometry.Spec (CommRingCat.of ↑R)).Modules)
:
A sheaf M on Spec R lies in the essential image of the tilde functor iff
the affine counit fromTildeΓ M is an isomorphism.
theorem
tilde_counit_isIso_of_presentation
{R : CommRingCat}
(M : (AlgebraicGeometry.Spec R).Modules)
(P : SheafOfModules.Presentation M)
:
If a sheaf of modules on Spec R admits a presentation, then the
affine counit fromTildeΓ is an isomorphism.