EtaleFundamentalGroups.Cohomology.constantFiniteH1Pullback_injective_of_fundamentalGroupHom_surjective
Surjectivity on actual fundamental groups implies injectivity of the already constructed derived H¹ pullback.
Source context 3 commands
Surrounding namespaces, section variables, and local commands at this declaration.
noncomputable section
open CategoryTheory AlgebraicGeometry
namespace EtaleFundamentalGroups.CohomologyLean source · statement
theorem constantFiniteH1Pullback_injective_of_fundamentalGroupHom_surjective
{X Y : Scheme} [ConnectedSpace X] [ConnectedSpace Y]
(f : X ⟶ Y) {Ω : Type} [Field Ω] [IsSepClosed Ω]
(geom : Spec (.of Ω) ⟶ X) (A : AddCommGrpCat.{0}) [Finite A]
(hf : Function.Surjective (FiniteEtale.fundamentalGroupHom f geom)) :
Function.Injective (constantCohomologyPullback f A 1)