Module

IsLocallyFreeOfRank_pushforward_of_forall_fibre.lean

Nyll.JacobianVarieties.Picard.IsLocallyFreeOfRank_pushforward_of_forall_fibre
1 declaration indexed from sourceView source ↗

Relative Picard varieties and fibre cohomology

Deduce local freeness of a pushforward line bundle from its fibre cohomology.

Imports12
Imported by8

Declarations

AlgebraicGeometry.RelPicard.isLocallyFreeOfRank_pushforward_of_forall_fibre
Source context 12 commands

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

section ProofImplementation
namespace JacobianVarieties.Picard.Proofs.IsLocallyFreeOfRank_pushforward_of_forall_fibre
attribute [-instance] AlgebraicGeometry.SmoothOfRelativeDimension.fiberToSpecResidueField
  AlgebraicGeometry.SmoothOfRelativeDimension.pullback_snd
  AlgebraicGeometry.SmoothOfRelativeDimension.pullback_fst
  AlgebraicGeometry.SmoothOfRelativeDimension.smooth_one
  AlgebraicGeometry.SmoothProperCurve.isIntegral_pullback_Spec_field
  AlgebraicGeometry.IsProper.fiberToSpecResidueField
attribute [-simp] AlgebraicGeometry.tilde.functorCompPullbackSpecIso_app
  TwoChartCech.Mumford.dK_apply TwoChartCech.Mumford.ι0_apply TwoChartCech.Mumford.ι1_apply
  TwoChartCech.KerCoprod.dK_apply TwoChartCech.KerCoprod.ι1_apply
  TwoChartCech.KerCoprod.ι0_apply AlgebraicGeometry.SmoothProperCurve.sectionBaseChange_coe_snd
  AlgebraicGeometry.SmoothProperCurve.sectionBaseChange_coe_fst
universe u
open _root_.CategoryTheory
open _root_.CategoryTheory.Limits
open _root_.AlgebraicGeometry
open _root_.AlgebraicGeometry.RelPicard
open _root_.NeronModelInfra
open _root_.CategoryTheory.MonoidalCategory
open _root_.AlgebraicGeometry.SmoothProperCurve
theorem _root_.AlgebraicGeometry.RelPicard.isLocallyFreeOfRank_pushforward_of_forall_fibre
    (R : Type u) [CommRing R] [IsNoetherianRing R] {C : Scheme.{u}} (c : C ⟶ Spec
      (CommRingCat.of R))
    [IsProper c] [SmoothOfRelativeDimension 1 c]
    (ε : SchemeHomOver (𝟙 (Spec (CommRingCat.of R))) c)
    (h𝔉 : ∀ m₀ : ℕ, ∃ 𝔉 : SmoothProperCurve.FiniteMapData c ε, m₀ ≤ 𝔉.m)
    {T : Scheme.{u}} (t : T ⟶ Spec (CommRingCat.of R)) [LocallyOfFiniteType t]
    (F : (pullback c t).Modules) (hF : Scheme.Modules.IsInvertible F) (n : ℕ)
    (hfib : ∀ (k : Type u) [Field k] (s : Spec (CommRingCat.of k) ⟶ T)
      (𝒲 : (pullback (pullback.snd c t) s).TwoAffineOpenCover),
      Subsingleton (𝒲.sectionsOf (fibreAt c t s) (fibreModule c t s F)).H1 ∧
        Module.finrank k (𝒲.sectionsOf (fibreAt c t s) (fibreModule c t s F)).H0 = n) :
    Scheme.Modules.IsLocallyFreeOfRank n ((Scheme.Modules.pushforward
      (pullback.snd c t)).obj F)