Situation 77.7.1. Let S be a scheme. Let f : X \to B be a morphism of algebraic spaces over S. Let u : \mathcal{F} \to \mathcal{G} be a homomorphism of quasi-coherent \mathcal{O}_ X-modules. For any scheme T over B we will denote u_ T : \mathcal{F}_ T \to \mathcal{G}_ T the base change of u to T, in other words, u_ T is the pullback of u via the projection morphism X_ T = X \times _ B T \to X. In this situation we can consider the functor
There are variants F_{inj}, F_{surj}, F_{zero} where we ask that u_ T is injective, surjective, or zero.
Comments (0)