The actual rational Picard scheme diamond is an internal group morphism

Proved

MazurTransfer.Order13ActualPicardSchemeNormGroupHom.schemeDiamond_isMonHom

by Vas · Oct 17, 2026 · Mathlib 0df444a (Lean v4.33.1)

algebraic-geometryarithmetic-geometrymazur-theorem

Let P be the same actual rational represented Picard scheme, with its original internal commutative group structure. The existing scheme diamond is an internal group morphism of P over Q. For pi and pi-bar, these are the original endomorphisms 3 id+2 delta and 5 id-2 delta, using the Picard group law. The named downstream consumers are the actual norm isogenies and their scheme kernels.

Preamble

/-
Copyright (c) 2026 Vas and contributors. Released under Apache-2.0.
Design boundary: the same actual Picard diamond and both nineteen-norm
endomorphisms are internal group morphisms, by preservation on all test
schemes. Named downstream consumer: scheme isogenies and descent kernels.
-/
import Definitions.Def_MazurTransfer_Order13ActualPicardSchemeNineteenNormData
import Theorems.Thm_MazurTransfer_MonoidObjectMorphismFromPointwiseGroupLaw_isMonHom_of_all_points

noncomputable section
open CategoryTheory AlgebraicGeometry AlgebraicGeometry.RelPicard
open NeronModelInfra GoodReductionJacobian MazurTransfer
open MazurTransfer.Order13ActualPicardDiamondSchemeEndomorphism
open MazurTransfer.Order13ActualPicardGeometricDiamondGroupAction
open MazurTransfer.Order13ActualPicardGenericFieldAction
open MazurTransfer.Order13ActualPicardSchemeNineteenNorm
open scoped CategoryTheory.MonObj
local instance publicStatementactualPicardDiamondGroupMorphismProvider120261017 : GrpObj (Over.mk actualPicard.toBase) :=
  (show RepresentsRelSubPic (MazurTorsion.XOneThirteenProjectiveCurve.curveToBase ℚ) infinitySection
    (algEquivZeroGroupCut (MazurTorsion.XOneThirteenProjectiveCurve.curveToBase ℚ) infinitySection).toSubPicCondition actualPicard from actualRepresentation).grpObj



local instance publicStatementactualPicardDiamondGroupMorphismProvider220261017 : Fact ((104 : ℚ) ≠ 0) := ⟨by norm_num⟩
local instance publicStatementactualPicardDiamondGroupMorphismProvider320261017 : Algebra ℚ (GoodCharacteristicGeometryPublicProof.MazurTransfer.Order13GoodCharacteristicCurveModel.actualCurveFunctionField ℚ) :=
  GoodCharacteristicGeometryPublicProof.MazurTransfer.Order13GoodCharacteristicCurveModel.actualCurveFunctionFieldAlgebra ℚ
local instance publicStatementactualPicardDiamondGroupMorphismProvider420261017 : IsCommMonObj (Over.mk actualPicard.toBase) :=
  (show RepresentsRelSubPic (MazurTorsion.XOneThirteenProjectiveCurve.curveToBase ℚ) infinitySection
    (algEquivZeroGroupCut (MazurTorsion.XOneThirteenProjectiveCurve.curveToBase ℚ) infinitySection).toSubPicCondition actualPicard from actualRepresentation).isCommMonObj

Formal statement

theorem MazurTransfer.Order13ActualPicardSchemeNormGroupHom.schemeDiamond_isMonHom : IsMonHom schemeDiamond := by sorry

Source

Complete original MazurTheorem Order13ActualPicardSchemeNormGroupHom.schemeDiamond_isMonHom, retaining the original full type, original helper arguments and original group-object and scalar providers. Uses the existing accepted public monoid Yoneda criterion and the same actual represented Picard and pullback action. Official Anthropic FLT Picard interfaces at 6e837e75355538c7f80bab5b956861e86c4eacc2, Apache-2.0.

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