noncomputable def
TopCat.Sheaf.sectionsFunctor
(C : Type u)
[CategoryTheory.Category.{v, u} C]
{X : TopCat}
(U : TopologicalSpace.Opens ↑X)
:
CategoryTheory.Functor (Sheaf C X) C
The sections functor Γ(U, –) : Sheaf C X → C sending a sheaf to its sections on
a fixed open U, constructed by forgetting to a presheaf and evaluating at U.
Instances For
theorem
noetherianSpace_sections_preservesFilteredColimits
(C : Type u)
[CategoryTheory.Category.{v, u} C]
{X : TopCat}
[TopologicalSpace.NoetherianSpace ↑X]
(U : TopologicalSpace.Opens ↑X)
:
Key Noetherian fact (used for higher direct images in Lec 11): on a Noetherian
topological space, the sections functor Γ(U, –) commutes with filtered colimits of
sheaves.