Module

Finite_H0_H1_structureSheaf_of_isAlgClosed.lean

Nyll.AlgebraicCurves.Cohomology.Finite_H0_H1_structureSheaf_of_isAlgClosed
3 declarations indexed from sourceView source ↗

Finiteness and dimensions of structure-sheaf cohomology over an algebraically closed field.

Declarations

AlgebraicCurves.Cohomology.Proofs.Finite_H0_H1_structureSheaf_of_isAlgClosed.AlgebraicCurve.ne_top_of_isAffineOpen'
Source context 12 commands

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

section ProofImplementation
namespace AlgebraicCurves.Cohomology.Proofs.Finite_H0_H1_structureSheaf_of_isAlgClosed
attribute [-instance] AlgebraicCurve.Place.instIsPrimeCenter
  AlgebraicCurve.Place.instIsFractionRingIntegralClosureAt
  instIsTorsionFreeSubtypeMemValuationSubringToValuationSubringIntegralClosureAt
  AlgebraicCurve.Place.instIsDedekindDomainIntegralClosureAt
  AlgebraicCurve.Place.instFiniteSubtypeMemValuationSubringToValuationSubringIntegralClosureAt
  AlgebraicCurve.RationalFunctionField.instNontrivialInftyValueGroup
attribute [-simp] AlgebraicCurve.Place.placeOfPrime_toValuationSubring
  AlgebraicCurve.Place.mem_fiberOver AlgebraicCurve.Place.fiberEquiv_symm_apply
  AlgebraicCurve.Place.fiberEquiv_apply AlgebraicCurve.Place.centerHeightOneSpectrum_asIdeal
attribute [-simp] AlgebraicCurve.RationalFunctionField.placeEquivOption_placeInfty
  AlgebraicCurve.RationalFunctionField.placeEquivOption_symm_some
  AlgebraicCurve.RationalFunctionField.placeEquivOption_placeOfPoint
  AlgebraicCurve.RationalFunctionField.placeEquivOption_symm_none
  AlgebraicCurve.Place.differentialCoeff_zero AlgebraicCurve.Place.differentialCoeff_dCoord
  AlgebraicCurve.TranscendenceTower.mk.sizeOf_spec AlgebraicCurve.IntegralBasisInLSpace.mk.injEq
  AlgebraicCurve.TranscendenceTower.mk.injEq
attribute [-simp] AlgebraicCurve.PoleDivisorPackage.mk.sizeOf_spec
  AlgebraicCurve.IntegralBasisInLSpace.mk.sizeOf_spec AlgebraicCurve.PoleDivisorPackage.mk.injEq
open CategoryTheory AlgebraicGeometry
universe u
namespace AlgebraicCurve
open _root_.AlgebraicCurve
open _root_.AlgebraicCurve
open CategoryTheory AlgebraicGeometry TopologicalSpace
theorem ne_top_of_isAffineOpen' {C : Scheme.{u}} (hC : ¬ IsAffine C) {U : C.Opens}
    (hU : IsAffineOpen U) : U ≠ ⊤
AlgebraicCurves.Cohomology.Proofs.Finite_H0_H1_structureSheaf_of_isAlgClosed.AlgebraicCurve.finite_H0_H1_structureSheaf_of_isAlgClosed'
Source context 12 commands

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

section ProofImplementation
namespace AlgebraicCurves.Cohomology.Proofs.Finite_H0_H1_structureSheaf_of_isAlgClosed
attribute [-instance] AlgebraicCurve.Place.instIsPrimeCenter
  AlgebraicCurve.Place.instIsFractionRingIntegralClosureAt
  instIsTorsionFreeSubtypeMemValuationSubringToValuationSubringIntegralClosureAt
  AlgebraicCurve.Place.instIsDedekindDomainIntegralClosureAt
  AlgebraicCurve.Place.instFiniteSubtypeMemValuationSubringToValuationSubringIntegralClosureAt
  AlgebraicCurve.RationalFunctionField.instNontrivialInftyValueGroup
attribute [-simp] AlgebraicCurve.Place.placeOfPrime_toValuationSubring
  AlgebraicCurve.Place.mem_fiberOver AlgebraicCurve.Place.fiberEquiv_symm_apply
  AlgebraicCurve.Place.fiberEquiv_apply AlgebraicCurve.Place.centerHeightOneSpectrum_asIdeal
attribute [-simp] AlgebraicCurve.RationalFunctionField.placeEquivOption_placeInfty
  AlgebraicCurve.RationalFunctionField.placeEquivOption_symm_some
  AlgebraicCurve.RationalFunctionField.placeEquivOption_placeOfPoint
  AlgebraicCurve.RationalFunctionField.placeEquivOption_symm_none
  AlgebraicCurve.Place.differentialCoeff_zero AlgebraicCurve.Place.differentialCoeff_dCoord
  AlgebraicCurve.TranscendenceTower.mk.sizeOf_spec AlgebraicCurve.IntegralBasisInLSpace.mk.injEq
  AlgebraicCurve.TranscendenceTower.mk.injEq
attribute [-simp] AlgebraicCurve.PoleDivisorPackage.mk.sizeOf_spec
  AlgebraicCurve.IntegralBasisInLSpace.mk.sizeOf_spec AlgebraicCurve.PoleDivisorPackage.mk.injEq
open CategoryTheory AlgebraicGeometry
universe u
namespace AlgebraicCurve
open _root_.AlgebraicCurve
open _root_.AlgebraicCurve
open CategoryTheory AlgebraicGeometry TopologicalSpace
theorem finite_H0_H1_structureSheaf_of_isAlgClosed' {K : Type u} [Field K] [IsAlgClosed K] {C :
    Scheme.{u}} (𝒱 : C.TwoAffineOpenCover)
    (c : C ⟶ Spec (CommRingCat.of K)) [IsIntegral C] [IsProper c] [SmoothOfRelativeDimension 1 c] :
    letI := (AlgebraicCurve.baseToFunctionField c).toAlgebra
    Module.Finite K (𝒱.structureSheafSections c).H0 ∧ Module.Finite K (𝒱.structureSheafSections
      c).H1 ∧
      Module.finrank K (𝒱.structureSheafSections c).H0 = 1 ∧
      Module.finrank K (𝒱.structureSheafSections c).H1 = AlgebraicCurve.genusFF K C.functionField
        := by
  let := (AlgebraicCurve.baseToFunctionField c).toAlgebra
  have hcurve : IsCurveOver K C.functionField :=
    isCurveOver_of_isIntegral_of_smoothOfRelativeDimension_one c (RingEquiv.refl _) (fun _ => rfl)
  have : Algebra.EssFiniteType K C.functionField := essFiniteType_functionField c
  have hNA := not_isAffine_of_isProper_of_smoothOfRelativeDimension_one c
  have hne0 : 𝒱.U0 ≠ ⊤ := ne_top_of_isAffineOpen' hNA 𝒱.isAffineOpen_U0
  have hne1 : 𝒱.U1 ≠ ⊤ := ne_top_of_isAffineOpen' hNA 𝒱.isAffineOpen_U1
  obtain ⟨-, ⟨v₀, -⟩, -⟩ :=
    placesOf_union_eq_univ_of_sup_eq_top c 𝒱.U0 𝒱.U1 𝒱.sup_eq_top hne0 hne1
  have hC : ConstantsAreBase K C.functionField :=
    constantsAreBase_of_deg_eq_one v₀ (IsCurveOver.deg_eq_one_of_isAlgClosed v₀)
  obtain ⟨-, hL0, γ, D₀, hγ⟩ := stichtenothGenusExists_of_isCurveOver hC
  obtain ⟨hf0, hf1, hrk0, hrk1⟩ :=
    finite_H0_H1_structureSheaf_of_smoothProperCurve 𝒱 c hcurve hL0 ⟨γ, D₀, hγ⟩
  exact ⟨hf0, hf1, hrk0.trans (ell_zero_eq_one_of_constantsAreBase hC), hrk1⟩
AlgebraicCurve.finite_H0_H1_structureSheaf_of_isAlgClosed
Source context 10 commands

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

section ProofImplementation
namespace AlgebraicCurves.Cohomology.Proofs.Finite_H0_H1_structureSheaf_of_isAlgClosed
attribute [-instance] AlgebraicCurve.Place.instIsPrimeCenter
  AlgebraicCurve.Place.instIsFractionRingIntegralClosureAt
  instIsTorsionFreeSubtypeMemValuationSubringToValuationSubringIntegralClosureAt
  AlgebraicCurve.Place.instIsDedekindDomainIntegralClosureAt
  AlgebraicCurve.Place.instFiniteSubtypeMemValuationSubringToValuationSubringIntegralClosureAt
  AlgebraicCurve.RationalFunctionField.instNontrivialInftyValueGroup
attribute [-simp] AlgebraicCurve.Place.placeOfPrime_toValuationSubring
  AlgebraicCurve.Place.mem_fiberOver AlgebraicCurve.Place.fiberEquiv_symm_apply
  AlgebraicCurve.Place.fiberEquiv_apply AlgebraicCurve.Place.centerHeightOneSpectrum_asIdeal
attribute [-simp] AlgebraicCurve.RationalFunctionField.placeEquivOption_placeInfty
  AlgebraicCurve.RationalFunctionField.placeEquivOption_symm_some
  AlgebraicCurve.RationalFunctionField.placeEquivOption_placeOfPoint
  AlgebraicCurve.RationalFunctionField.placeEquivOption_symm_none
  AlgebraicCurve.Place.differentialCoeff_zero AlgebraicCurve.Place.differentialCoeff_dCoord
  AlgebraicCurve.TranscendenceTower.mk.sizeOf_spec AlgebraicCurve.IntegralBasisInLSpace.mk.injEq
  AlgebraicCurve.TranscendenceTower.mk.injEq
attribute [-simp] AlgebraicCurve.PoleDivisorPackage.mk.sizeOf_spec
  AlgebraicCurve.IntegralBasisInLSpace.mk.sizeOf_spec AlgebraicCurve.PoleDivisorPackage.mk.injEq
open CategoryTheory AlgebraicGeometry
universe u
open _root_.AlgebraicCurves.Cohomology.Proofs in
open _root_.AlgebraicCurve Finite_H0_H1_structureSheaf_of_isAlgClosed.AlgebraicCurve in
theorem _root_.AlgebraicCurve.finite_H0_H1_structureSheaf_of_isAlgClosed {K : Type u} [Field K]
    [IsAlgClosed K] {C : Scheme.{u}} (𝒱 : C.TwoAffineOpenCover)
    (c : C ⟶ Spec (CommRingCat.of K)) [IsIntegral C] [IsProper c] [SmoothOfRelativeDimension 1 c] :
    letI := (AlgebraicCurve.baseToFunctionField c).toAlgebra
    Module.Finite K (𝒱.structureSheafSections c).H0 ∧ Module.Finite K (𝒱.structureSheafSections
      c).H1 ∧
      Module.finrank K (𝒱.structureSheafSections c).H0 = 1 ∧
      Module.finrank K (𝒱.structureSheafSections c).H1 = AlgebraicCurve.genusFF K C.functionField :=
  finite_H0_H1_structureSheaf_of_isAlgClosed' 𝒱 c