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Atlas.AlgebraicGeometryI.code.QCohLocalization

@[reducible, inline]
abbrev QCohLocalization.ModuleTilde (R : Type u_1) [CommRing R] (M : Type u_2) [AddCommGroup M] [Module R M] (f : R) :
Type (max u_2 u_1)

The localized module M_f := S^{-1} M at the powers of f, encoding the value Γ(D(f), M̃) of the tilde sheaf on a principal open.

Instances For
    theorem QCohLocalization.localization_preserves_injective {R : Type u_1} [CommRing R] (S : Submonoid R) {M : Type u_2} {N : Type u_3} [AddCommGroup M] [Module R M] [AddCommGroup N] [Module R N] (f : M →ₗ[R] N) (hf : Function.Injective f) :

    Localization is left exact: it preserves injectivity of module maps.

    Localization is right exact: it preserves surjectivity of module maps.

    theorem QCohLocalization.localization_exact_middle {R : Type u_1} [CommRing R] (S : Submonoid R) {M' : Type u_2} {M : Type u_3} {M'' : Type u_4} [AddCommGroup M'] [Module R M'] [AddCommGroup M] [Module R M] [AddCommGroup M''] [Module R M''] (f : M' →ₗ[R] M) (g : M →ₗ[R] M'') (hex : Function.Exact f g) :

    Localization is exact in the middle: it preserves exactness of a pair f, g of consecutive linear maps.

    theorem QCohLocalization.localization_preserves_exactness {R : Type u_1} [CommRing R] (S : Submonoid R) {M : Type u_2} {N : Type u_3} {P : Type u_4} [AddCommGroup M] [Module R M] [AddCommGroup N] [Module R N] [AddCommGroup P] [Module R P] (f : M →ₗ[R] N) (g : N →ₗ[R] P) (hfg : Function.Exact f g) :

    Localization functor S^{-1}(−) is exact: it preserves exact sequences, the key property powering the tilde-functor proofs.

    Every quasi-coherent sheaf on Spec R lies in the essential image of the tilde functor (the Thm 12.1 direction).

    Global sections of a sheaf of modules on Spec R, viewed as an R-module through the natural Γ functor.

    Instances For

      The unit of the tilde ⊣ Γ adjunction is an isomorphism, expressing the identity Γ(M̃) ≅ M.

      The sheaf on Spec R is quasi-coherent for any R-module M.