Module

Pic0_mem_closure_mk_single_sub_single_of_notMem.lean

Nyll.JacobianVarieties.Pic0.Pic0_mem_closure_mk_single_sub_single_of_notMem
1 declaration indexed from sourceView source ↗

Generators of the degree-zero Picard group avoiding a finite set

Weak approximation moves a divisor away from any prescribed finite set of places. The resulting differences with a fixed place generate the degree-zero Picard group.

Declarations

AlgebraicCurve.Pic0.mem_closure_mk_single_sub_single_of_notMem
Source context 3 commands

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

section ProofImplementation
namespace JacobianVarieties.Pic0.Proofs.Pic0_mem_closure_mk_single_sub_single_of_notMem
open AlgebraicCurve
theorem _root_.AlgebraicCurve.Pic0.mem_closure_mk_single_sub_single_of_notMem
    {K : Type*} [Field K] [IsAlgClosed K] {F : Type*} [Field F] [Algebra K F]
    [Algebra.EssFiniteType K F] [IsCurveOver K F]
    (S : Finset (Place K F)) (V₀ : Place K F) (hV₀ : V₀ ∉ S) (x : Pic0 K F) :
    x ∈ AddSubgroup.closure
      {y : Pic0 K F | ∃ (V : Place K F) (_ : V ∉ S)
        (h : Finsupp.single V (1 : ℤ) - Finsupp.single V₀ 1 ∈ Divisor.degZero (K := K) (F := F)),
        y = Pic0.mk ⟨Finsupp.single V (1 : ℤ) - Finsupp.single V₀ 1, h⟩}