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The Stacks project

Lemma 6.26.4. Let (f, f^\sharp ) : (X, \mathcal{O}_ X) \to (Y, \mathcal{O}_ Y) be a morphism of ringed spaces. Let \mathcal{G} be a sheaf of \mathcal{O}_ Y-modules. Let x \in X. Then

(f^*\mathcal{G})_ x = \mathcal{G}_{f(x)} \otimes _{\mathcal{O}_{Y, f(x)}} \mathcal{O}_{X, x}

as \mathcal{O}_{X, x}-modules where the tensor product on the right uses f^\sharp _ x : \mathcal{O}_{Y, f(x)} \to \mathcal{O}_{X, x}.

Proof. This follows from Lemma 6.20.3 and the identification of the stalks of pullback sheaves at x with the corresponding stalks at f(x). See the formulae in Section 6.23 for example. \square


Comments (2)

Comment #746 by Anfang Zhou on

Typo. It should be

Comment #752 by on

Thanks for the comment. I have fixed this as well as the other typo you pointed out. See this commit.

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  • 3 comment(s) on Section 6.26: Morphisms of ringed spaces and modules

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