Module

Pic0_roof_package_of_surjective.lean

Nyll.JacobianVarieties.Pic0.Pic0_roof_package_of_surjective
2 declarations indexed from sourceView source ↗

Picard pullback along a surjective field morphism

A surjective morphism has degree one. Its divisor pullback and pushforward are inverse, and conjugating field automorphisms yields the corresponding Picard equivariance.

Declarations

JacobianVarieties.Pic0.Proofs.Pic0_roof_package_of_surjective.ROOFID.finiteAlong_and_finrankAlong_eq_one
Source context 9 commands

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

section ProofImplementation
namespace JacobianVarieties.Pic0.Proofs.Pic0_roof_package_of_surjective
attribute [-instance]
  AlgebraicCurve.Place.instIsRankOneDiscreteWithZeroMultiplicativeIntAdicValuation
  AlgebraicCurve.Place.instIsTrivialOnWithZeroMultiplicativeIntAdicValuation
  AlgebraicCurve.Place.instIsPrimeCenter AlgebraicCurve.Place.instIsFractionRingIntegralClosureAt
attribute [-instance]
  instIsTorsionFreeSubtypeMemValuationSubringToValuationSubringIntegralClosureAt
attribute [-instance]
  AlgebraicCurve.Place.instIsDedekindDomainIntegralClosureAt
  AlgebraicCurve.Place.instFiniteSubtypeMemValuationSubringToValuationSubringIntegralClosureAt
attribute [-simp]
  AlgebraicCurve.Place.congrEquiv_symm_apply
  AlgebraicCurve.RationalFunctionField.heightOneSpectrumOfIrreducible_asIdeal
  AlgebraicCurve.Place.congrRingEquiv_toValuationSubring AlgebraicCurve.Place.congrEquiv_apply
  AlgebraicCurve.Place.coe_comapSymmRingEquiv_apply
  AlgebraicCurve.RationalFunctionField.deg_placeOfPoint
  AlgebraicCurve.Place.placeOfPrime_toValuationSubring AlgebraicCurve.Place.mem_fiberOver
  AlgebraicCurve.Place.fiberEquiv_symm_apply AlgebraicCurve.Place.fiberEquiv_apply
  AlgebraicCurve.Place.centerHeightOneSpectrum_asIdeal
open AlgebraicCurve
namespace ROOFID
variable {K F₁ F₂ : Type} [Field K] [Field F₁] [Field F₂] [Algebra K F₁] [Algebra K F₂]
theorem finiteAlong_and_finrankAlong_eq_one (ι : F₁ →ₐ[K] F₂) (hιs : Function.Surjective ι) :
    FiniteAlong K ι ∧ finrankAlong K ι = 1
AlgebraicCurve.Pic0.roof_package_of_surjective
Source context 7 commands

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

section ProofImplementation
namespace JacobianVarieties.Pic0.Proofs.Pic0_roof_package_of_surjective
attribute [-instance]
  AlgebraicCurve.Place.instIsRankOneDiscreteWithZeroMultiplicativeIntAdicValuation
  AlgebraicCurve.Place.instIsTrivialOnWithZeroMultiplicativeIntAdicValuation
  AlgebraicCurve.Place.instIsPrimeCenter AlgebraicCurve.Place.instIsFractionRingIntegralClosureAt
attribute [-instance]
  instIsTorsionFreeSubtypeMemValuationSubringToValuationSubringIntegralClosureAt
attribute [-instance]
  AlgebraicCurve.Place.instIsDedekindDomainIntegralClosureAt
  AlgebraicCurve.Place.instFiniteSubtypeMemValuationSubringToValuationSubringIntegralClosureAt
attribute [-simp]
  AlgebraicCurve.Place.congrEquiv_symm_apply
  AlgebraicCurve.RationalFunctionField.heightOneSpectrumOfIrreducible_asIdeal
  AlgebraicCurve.Place.congrRingEquiv_toValuationSubring AlgebraicCurve.Place.congrEquiv_apply
  AlgebraicCurve.Place.coe_comapSymmRingEquiv_apply
  AlgebraicCurve.RationalFunctionField.deg_placeOfPoint
  AlgebraicCurve.Place.placeOfPrime_toValuationSubring AlgebraicCurve.Place.mem_fiberOver
  AlgebraicCurve.Place.fiberEquiv_symm_apply AlgebraicCurve.Place.fiberEquiv_apply
  AlgebraicCurve.Place.centerHeightOneSpectrum_asIdeal
open AlgebraicCurve
theorem _root_.AlgebraicCurve.Pic0.roof_package_of_surjective
    {K F₀ F₁ F₂ : Type} [Field K] [CharZero K] [Field F₀] [Field F₁] [Field F₂]
    [Algebra K F₀] [Algebra K F₁] [Algebra K F₂]
    [HasPrincipalDivisors K F₁] [HasPrincipalDivisors K F₂]
    (ι : F₁ →ₐ[K] F₂) (hι : ι.toRingHom.IsIntegral) (hFI : FundamentalIdentityAlong K ι hι)
    (hιs : Function.Surjective ι)
    (α : F₀ →ₐ[K] F₁) (hα : α.toRingHom.IsIntegral) (hια : (ι.comp α).toRingHom.IsIntegral)
    (W : F₁ ≃ₐ[K] F₁) :
    (∀ D : Divisor K F₁, Divisor.pushforwardAlong ι hι (Divisor.pullbackAlong ι hι D) = D) ∧
    Function.Surjective (Pic0.pullbackAlongHom ι hι hFI) ∧
    (∀ D : Divisor K F₁,
      Divisor.pushforwardAlong (ι.comp α) hια (Divisor.pullbackAlong ι hι D) =
        Divisor.pushforwardAlong α hα D) ∧
    ∃ θ : F₂ ≃ₐ[K] F₂, (∀ a : F₁, θ (ι a) = ι (W.symm a)) ∧
      ∀ x₁ : Pic0 K F₁,
        SemilinearAut.ofAlgAut θ • Pic0.pullbackAlongHom ι hι hFI x₁ =
          Pic0.pullbackAlongHom ι hι hFI (SemilinearAut.ofAlgAut W.symm • x₁)