Inverse curve pullback transports the actual closed-point place sets by the specified field action
DefinitionMazurTransfer_Order13FieldCurveInversePlaceSetDataalgebraic-geometryarithmetic-geometrymazur-theorem
Over every characteristic-zero field, membership in placesOf on the actual curve is characterized by its literal closed points, and inverse pullback by the original generic-compatible curve lift transports those place sets by the specified field automorphism. Both complete original types and the original local scalar algebra provider are compared. Named downstream consumer: full divisor-presentation pullback on the actual field curve.
Definition code
/-
Copyright (c) 2026 Vas and contributors. Released under Apache-2.0.
Design boundary: inverse-curve preimages of opens transport the literal
sets of closed-point valuation places by the field automorphism. Named
downstream consumer: the range condition for transformed divisor presentations.
-/
import Definitions.Def_MazurTransfer_Order13FieldDiamondGenericCurveOrderData
import Definitions.Def_AlgebraicCurve_PlacesOf
noncomputable section
universe u
namespace MazurTransfer.Order13FieldCurveInversePlaceSet
open CategoryTheory AlgebraicGeometry AlgebraicCurve
open MazurTorsion.XOneThirteenProjectiveCurve
open Order13FieldCurveAutomorphismLift Order13FieldDiamondGenericCurveOrder
open CurveClosedPointImage
open GoodCharacteristicGeometryPublicProof.MazurTransfer.Order13GoodCharacteristicCurveModel
variable (K : Type u) [Field K] [CharZero K]
local instance : Fact ((104 : K) ≠ 0) := ⟨by norm_num⟩
local notation "C" => curveScheme K
local notation "F" => actualCurveFunctionField K
local instance : Algebra K F := actualCurveFunctionFieldAlgebra K
theorem mem_placesOf_actual_iff (U : (curveScheme K).Opens) (v : Place K F) :
v ∈ placesOf (curveToBase K) U ↔
∃ x : closedPoints C, x.1 ∈ U ∧ actualPlaceOfPoint K x = v := by
constructor
· rintro ⟨x, hxU, hx, hv⟩
refine ⟨⟨x, hx⟩, hxU, ?_⟩
have hR : (actualPlaceOfPoint K ⟨x, hx⟩).toValuationSubring.toSubring =
v.toValuationSubring.toSubring := (actualPlaceOfPoint_stalk_range K ⟨x, hx⟩).symm.trans hv
apply Place.ext
ext a
exact Iff.of_eq (congrArg (fun R : Subring F => a ∈ R) hR)
· rintro ⟨x, hxU, rfl⟩
exact ⟨x.1, hxU, x.2, actualPlaceOfPoint_stalk_range K x⟩
theorem inverse_placesOf (σ : F ≃ₐ[K] F) (U : (curveScheme K).Opens) :
placesOf (curveToBase K) ((fieldLift K σ).inv ⁻¹ᵁ U) =
(fun v : Place K F => σ • v) '' placesOf (curveToBase K) U := by
ext v
constructor
· intro hv
obtain ⟨x, hx, rfl⟩ := (mem_placesOf_actual_iff K _ _).mp hv
let y := closedPointImage (fieldLift K σ).symm x
have hy : actualPlaceOfPoint K y = σ⁻¹ • actualPlaceOfPoint K x := by
have h := fieldLift_place K σ⁻¹ x
rw [fieldLift_inv K] at h
exact h
refine ⟨actualPlaceOfPoint K y, (mem_placesOf_actual_iff K U _).mpr ⟨y, hx, rfl⟩, ?_⟩
change σ • actualPlaceOfPoint K y = actualPlaceOfPoint K x
rw [hy, smul_inv_smul]
· rintro ⟨w, hw, rfl⟩
obtain ⟨y, hy, rfl⟩ := (mem_placesOf_actual_iff K U w).mp hw
let x := closedPointImage (fieldLift K σ) y
apply (mem_placesOf_actual_iff K _ _).mpr
refine ⟨x, ?_, fieldLift_place K σ y⟩
change (fieldLift K σ).inv ((fieldLift K σ).hom y.1) ∈ U
have h : (fieldLift K σ).inv ((fieldLift K σ).hom y.1) = y.1 := by
exact congrArg (fun f : C ⟶ C => f y.1) (fieldLift K σ).hom_inv_id
rw [h]
exact hy
end MazurTransfer.Order13FieldCurveInversePlaceSet
#print axioms MazurTransfer.Order13FieldCurveInversePlaceSet.inverse_placesOf
Source
Complete original MazurTheorem geometric diamond/closed-point transport statements and proofs, with public original map and isomorphism constructors. The original base-map compatibility statement is a checked bridge from the accepted Cartesian-square theorem. Official Anthropic FLT at 6e837e75355538c7f80bab5b956861e86c4eacc2, Apache-2.0.