Module

GenericCohomologyNaturality.lean

Nyll.AnabelianGeometry.WeightFiltration.GenericCohomologyNaturality
1 declaration indexed from sourceView source ↗

Actual H¹ pullback at the generic point

Restriction to the function field commutes with dominant scheme pullback. Both sides use the existing derived-sheaf maps, rather than a replacement cohomology model or an assumed compatibility square.

Declarations

AnabelianGeometry.WeightFiltration.finiteH1Pullback_genericPoint

The actual generic-point square induces the corresponding commutative square on derived finite-coefficient H¹.

Source context 2 commands

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

open AlgebraicGeometry CategoryTheory EtaleFundamentalGroups.Cohomology
namespace AnabelianGeometry.WeightFiltration
theorem finiteH1Pullback_genericPoint
    {X Y : Scheme} [IsIntegral X] [IsIntegral Y]
    (f : X ⟶ Y) (hf : DenseRange f)
    {Ω : Type} [Field Ω] [IsSepClosed Ω]
    (η : Spec (.of Ω) ⟶ Spec (.of X.functionField))
    (A : AddCommGrpCat.{0}) [Finite A]
    (a : Sheaf.H.{0} ((constantSheaf Y.smallEtaleTopology AddCommGrpCat.{0}).obj A) 1) :
    constantCohomologyPullback (X.fromSpecStalk (genericPoint X)) A 1
        (constantCohomologyPullback f A 1 a) =
      constantCohomologyPullback (Spec.map (CommRingCat.ofHom (f.functionFieldMap hf))) A 1
        (constantCohomologyPullback (Y.fromSpecStalk (genericPoint Y)) A 1 a)