Module

nonempty_pullback_sectionIdeal_pow_module_iso_of_smoothLocus.lean

Nyll.JacobianVarieties.Picard.nonempty_pullback_sectionIdeal_pow_module_iso_of_smoothLocus
4 declarations indexed from sourceView source ↗

Powers of the section ideal under base change on the smooth locus

The section ideal is invertible when the section lies in the relative smooth curve locus. Its powers commute with base change, and the invertible-ideal comparison identifies the associated pulled-back modules.

Imports27
Imported by2

Declarations

JacobianVarieties.Picard.Proofs.SmoothSectionPower.AlgebraicGeometry.RelPicard.IdealBC.comap_pow
Source context 13 commands

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

section ProofImplementation
namespace JacobianVarieties.Picard.Proofs.SmoothSectionPower
universe u
open _root_.CategoryTheory
open _root_.CategoryTheory.Limits
open _root_.AlgebraicGeometry
open _root_.AlgebraicGeometry.RelPicard
open _root_.NeronModelInfra
namespace AlgebraicGeometry
namespace RelPicard
namespace IdealBC
open _root_.AlgebraicGeometry.RelPicard
open _root_.AlgebraicGeometry
theorem comap_pow {X Y : Scheme.{u}} (I : Y.IdealSheafData) (f : X ⟶ Y) (n : ℕ) :
    (I ^ n).comap f = (I.comap f) ^ n
JacobianVarieties.Picard.Proofs.SmoothSectionPower.AlgebraicGeometry.RelPicard.IdealBC.sectionIdeal_comap
Source context 14 commands

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

section ProofImplementation
namespace JacobianVarieties.Picard.Proofs.SmoothSectionPower
universe u
open _root_.CategoryTheory
open _root_.CategoryTheory.Limits
open _root_.AlgebraicGeometry
open _root_.AlgebraicGeometry.RelPicard
open _root_.NeronModelInfra
namespace AlgebraicGeometry
namespace RelPicard
namespace IdealBC
open _root_.AlgebraicGeometry.RelPicard
open _root_.AlgebraicGeometry
variable {R : Type u} [CommRing R] {C : Scheme.{u}}
theorem sectionIdeal_comap (c : C ⟶ Spec (CommRingCat.of R)) [IsSeparated c]
    (ε : SchemeHomOver (𝟙 (Spec (CommRingCat.of R))) c) {T T' : Scheme.{u}}
    {t : T ⟶ Spec (CommRingCat.of R)} {t' : T' ⟶ Spec (CommRingCat.of R)}
    (ψ : SchemeHomOver t' t) :
    (RelPicard.sectionIdeal c ε t).comap (RelPicard.baseChangeSnd c ψ) =
      RelPicard.sectionIdeal c ε t'
JacobianVarieties.Picard.Proofs.SmoothSectionPower.AlgebraicGeometry.RelPicard.IdealBC.isInvertible_sectionIdeal
Source context 14 commands

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

section ProofImplementation
namespace JacobianVarieties.Picard.Proofs.SmoothSectionPower
universe u
open _root_.CategoryTheory
open _root_.CategoryTheory.Limits
open _root_.AlgebraicGeometry
open _root_.AlgebraicGeometry.RelPicard
open _root_.NeronModelInfra
namespace AlgebraicGeometry
namespace RelPicard
namespace IdealBC
open _root_.AlgebraicGeometry.RelPicard
open _root_.AlgebraicGeometry
variable {R : Type u} [CommRing R] {C : Scheme.{u}}
theorem isInvertible_sectionIdeal (c : C ⟶ Spec (CommRingCat.of R))
    [IsSeparated c] (U : C.Opens) [SmoothOfRelativeDimension 1 (U.ι ≫ c)]
    (ε : SchemeHomOver (𝟙 (Spec (CommRingCat.of R))) c) (hεU : Set.range ε.1 ⊆ (U : Set C))
    {T : Scheme.{u}} (t : T ⟶ Spec (CommRingCat.of R)) :
    (RelPicard.sectionIdeal c ε t).IsInvertible
AlgebraicGeometry.RelPicard.nonempty_pullback_sectionIdeal_pow_module_iso_of_smoothLocus
Source context 10 commands

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

section ProofImplementation
namespace JacobianVarieties.Picard.Proofs.SmoothSectionPower
universe u
open _root_.CategoryTheory
open _root_.CategoryTheory.Limits
open _root_.AlgebraicGeometry
open _root_.AlgebraicGeometry.RelPicard
open _root_.NeronModelInfra
open AlgebraicGeometry.RelPicard.IdealBC in
with_weak_namespace _root_.AlgebraicGeometry.RelPicard
theorem nonempty_pullback_sectionIdeal_pow_module_iso_of_smoothLocus
    (R : Type u) [CommRing R] {C : Scheme.{u}} (c : C ⟶ Spec (CommRingCat.of R)) [IsSeparated c]
    (U : C.Opens) [SmoothOfRelativeDimension 1 (U.ι ≫ c)]
    (ε : SchemeHomOver (𝟙 (Spec (CommRingCat.of R))) c) (hεU : Set.range ε.1 ⊆ (U : Set C))
    {T T' : Scheme.{u}} {t : T ⟶ Spec (CommRingCat.of R)} {t' : T' ⟶ Spec (CommRingCat.of R)}
    (ψ : SchemeHomOver t' t) (r : ℕ) :
    Nonempty
      ((Scheme.Modules.pullback (baseChangeSnd c ψ)).obj (((sectionIdeal c ε t) ^ r).module) ≅
      ((sectionIdeal c ε t') ^ r).module)