Module

FiniteH1PullbackComposition.lean

Nyll.EtaleFundamentalGroups.Cohomology.FiniteH1PullbackComposition
1 declaration indexed from sourceView source ↗

Composition for actual finite-coefficient H¹ pullback

This is the composition law for the existing derived-sheaf pullback, obtained from the faithful character comparison, including its geometric base points.

Declarations

EtaleFundamentalGroups.Cohomology.constantFiniteH1Pullback_comp

Actual derived finite-coefficient H¹ pullback is contravariantly compatible with composition of connected scheme morphisms.

Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
open CategoryTheory AlgebraicGeometry
namespace EtaleFundamentalGroups.Cohomology
theorem constantFiniteH1Pullback_comp
    {X Y Z : Scheme} [ConnectedSpace X] [ConnectedSpace Y] [ConnectedSpace Z]
    (f : X ⟶ Y) (g : Y ⟶ Z)
    {Ω : Type} [Field Ω] [IsSepClosed Ω]
    (geom : Spec (.of Ω) ⟶ X) (A : AddCommGrpCat.{0}) [Finite A]
    (c : Sheaf.H.{0} ((constantSheaf Z.smallEtaleTopology AddCommGrpCat.{0}).obj A) 1) :
    constantCohomologyPullback (f ≫ g) A 1 c =
      constantCohomologyPullback f A 1 (constantCohomologyPullback g A 1 c)