Module

InfinitePlaceOverfield.lean

Nyll.ClassFieldTheory.GlobalClassFieldTheory.Reciprocity.ComplexificationArtin.InfinitePlaceOverfield
38 declarations indexed from sourceView source ↗

The complex-conjugation overfield at an infinite place

This module realizes the embedded field L(i) inside ℂ, constructs its complex place, and identifies ambient complex conjugation on that field.

Declarations

GlobalClassFieldTheory.Reciprocity.complexEmbeddingFieldRange_map_complexConjugation

The field range of a complex embedding is preserved by complex conjugation when a relative automorphism realizes that conjugation.

Source context 7 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
theorem complexEmbeddingFieldRange_map_complexConjugation
    (φ : L →+* ℂ)
    (σ : L ≃ₐ[K] L)
    (hσ : NumberField.ComplexEmbedding.IsConj φ σ) :
    φ.toRatAlgHom.fieldRange.map
        (Complex.conjAe.restrictScalars ℚ).toAlgHom =
      φ.toRatAlgHom.fieldRange
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield

The concrete field L(i) inside ℂ, formed using the complex embedding belonging to the chosen place above v.

Source context 8 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
def infinitePlaceComplexificationOverfield
    (v : InfinitePlace K) :
    IntermediateField ℚ ℂ
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfieldRationalAlgebra
Source context 8 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield_finiteDimensional
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceComplexificationOverfield_finiteDimensional
    (v : InfinitePlace K) :
    FiniteDimensional ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield_numberField
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceComplexificationOverfield_numberField
    (v : InfinitePlace K) :
    NumberField
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfieldEmbedding

The chosen top-field embedding L → L(i).

Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
def infinitePlaceComplexificationOverfieldEmbedding
    (v : InfinitePlace K) :
    L →ₐ[ℚ]
      infinitePlaceComplexificationOverfield
        (K := K) (L := L) v
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfieldEmbedding_coe

The chosen embedding into the complexification overfield agrees with the original complex embedding after coercion to ℂ.

Source context 10 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
omit [NumberField K] [FiniteDimensional K L] in
theorem infinitePlaceComplexificationOverfieldEmbedding_coe
    (v : InfinitePlace K) (x : L) :
    ((infinitePlaceComplexificationOverfieldEmbedding
        (K := K) (L := L) v x :
      infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) : ℂ) =
      InfinitePlace.embedding
        (chosenInfinitePlaceAbove (L := L) v) x
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield_algebra
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceComplexificationOverfield_algebra
    (v : InfinitePlace K) :
    Algebra L
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield_smul

The scalar action belonging to the chosen top-field embedding.

Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceComplexificationOverfield_smul
    (v : InfinitePlace K) :
    SMul L
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield_ratScalarTower
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceComplexificationOverfield_ratScalarTower
    (v : InfinitePlace K) :
    IsScalarTower ℚ L
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield_baseAlgebra
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceComplexificationOverfield_baseAlgebra
    (v : InfinitePlace K) :
    Algebra K
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield_baseSmul

The scalar action induced from the original base-field embedding.

Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceComplexificationOverfield_baseSmul
    (v : InfinitePlace K) :
    SMul K
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield_baseRatScalarTower
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceComplexificationOverfield_baseRatScalarTower
    (v : InfinitePlace K) :
    IsScalarTower ℚ K
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield_scalarTower
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceComplexificationOverfield_scalarTower
    (v : InfinitePlace K) :
    IsScalarTower K L
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield_finiteDimensional_over_extension
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceComplexificationOverfield_finiteDimensional_over_extension
    (v : InfinitePlace K) :
    FiniteDimensional L
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.rationalComplexificationEmbeddingInInfinitePlaceOverfield

The cyclotomic fourth-root field embeds into the concrete overfield through its copy in ℂ.

Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
def
    rationalComplexificationEmbeddingInInfinitePlaceOverfield
    (v : InfinitePlace K) :
    rationalComplexificationCyclotomicField →ₐ[ℚ]
      infinitePlaceComplexificationOverfield
        (K := K) (L := L) v
GlobalClassFieldTheory.Reciprocity.rationalComplexification_infinitePlaceOverfield_algebra
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    rationalComplexification_infinitePlaceOverfield_algebra
    (v : InfinitePlace K) :
    Algebra rationalComplexificationCyclotomicField
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.rationalComplexification_infinitePlaceOverfield_smul

The scalar action induced by the concrete fourth-root-field embedding. Declaring it directly keeps instance search away from unrelated intermediate-field algebra structures.

Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    rationalComplexification_infinitePlaceOverfield_smul
    (v : InfinitePlace K) :
    SMul rationalComplexificationCyclotomicField
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.rationalComplexification_infinitePlaceOverfield_scalarTower
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    rationalComplexification_infinitePlaceOverfield_scalarTower
    (v : InfinitePlace K) :
    IsScalarTower ℚ rationalComplexificationCyclotomicField
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceEmbeddedExtensionField

The copy of the given abelian extension inside the concrete complexification overfield, viewed over the original base field.

Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
def infinitePlaceEmbeddedExtensionField
    (v : InfinitePlace K) :
    IntermediateField K
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceEmbeddedExtensionField_isAbelianGalois
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceEmbeddedExtensionField_isAbelianGalois
    (v : InfinitePlace K) :
    IsAbelianGalois K
      (infinitePlaceEmbeddedExtensionField
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceBaseFourthRootField

The fourth-root cyclotomic factor over the original base field, inside the concrete complexification overfield.

Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
def infinitePlaceBaseFourthRootField
    (v : InfinitePlace K) :
    IntermediateField K
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceBaseFourthRootField_isCyclotomic
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceBaseFourthRootField_isCyclotomic
    (v : InfinitePlace K) :
    IsCyclotomicExtension {4} K
      (infinitePlaceBaseFourthRootField
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceBaseFourthRootField_isAbelianGalois
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceBaseFourthRootField_isAbelianGalois
    (v : InfinitePlace K) :
    IsAbelianGalois K
      (infinitePlaceBaseFourthRootField
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceRatEmbeddedExtensionField
Source context 10 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
omit [FiniteDimensional K L] in
def infinitePlaceRatEmbeddedExtensionField
    (v : InfinitePlace K) :
    IntermediateField ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceRatFourthRootField
Source context 10 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
omit [FiniteDimensional K L] in
def infinitePlaceRatFourthRootField
    (v : InfinitePlace K) :
    IntermediateField ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceRatComplexificationFactors
Source context 10 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
omit [FiniteDimensional K L] in
def infinitePlaceRatComplexificationFactors
    (v : InfinitePlace K) :
    IntermediateField ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceRatEmbeddedExtensionField_le_factors
Source context 10 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
omit [FiniteDimensional K L] in
theorem infinitePlaceRatEmbeddedExtensionField_le_factors
    (v : InfinitePlace K) :
    infinitePlaceRatEmbeddedExtensionField
          (K := K) (L := L) v ≤
      infinitePlaceRatComplexificationFactors
          (K := K) (L := L) v
GlobalClassFieldTheory.Reciprocity.infinitePlaceRatFourthRootField_le_factors
Source context 10 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
omit [FiniteDimensional K L] in
theorem infinitePlaceRatFourthRootField_le_factors
    (v : InfinitePlace K) :
    infinitePlaceRatFourthRootField
          (K := K) (L := L) v ≤
      infinitePlaceRatComplexificationFactors
          (K := K) (L := L) v
GlobalClassFieldTheory.Reciprocity.infinitePlaceRatComplexificationFactors_sup
Source context 10 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
omit [NumberField K] [FiniteDimensional K L] in
theorem infinitePlaceRatComplexificationFactors_sup
    (v : InfinitePlace K) :
    infinitePlaceRatEmbeddedExtensionField
          (K := K) (L := L) v ⊔
        infinitePlaceRatFourthRootField
          (K := K) (L := L) v =
      ⊤
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationFactors_sup

The embedded abelian extension and the base-changed fourth-root factor generate the whole concrete complexification overfield.

Source context 10 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
omit [FiniteDimensional K L] in
theorem infinitePlaceComplexificationFactors_sup
    (v : InfinitePlace K) :
    infinitePlaceEmbeddedExtensionField
          (K := K) (L := L) v ⊔
        infinitePlaceBaseFourthRootField
          (K := K) (L := L) v =
      ⊤
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield_isAbelianGalois_over_base
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceComplexificationOverfield_isAbelianGalois_over_base
    (v : InfinitePlace K) :
    IsAbelianGalois K
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield_isTotallyComplex
Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
instance
    infinitePlaceComplexificationOverfield_isTotallyComplex
    (v : InfinitePlace K) :
    IsTotallyComplex
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfieldComplexPlace

The infinite place on the concrete overfield induced by its inclusion into ℂ.

Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
def infinitePlaceComplexificationOverfieldComplexPlace
    (v : InfinitePlace K) :
    InfinitePlace
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v)
GlobalClassFieldTheory.Reciprocity.infinitePlaceComplexificationOverfield_map_complexConjugation

Complex conjugation preserves the concrete overfield L(i) at a ramified chosen place. Preservation of the L-factor is the actual local Artin value being a conjugation; preservation of the fourth-root factor is intrinsic.

Source context 10 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
omit [NumberField K] [FiniteDimensional K L] in
theorem infinitePlaceComplexificationOverfield_map_complexConjugation
    (v : InfinitePlace K)
    (hRamified :
      (chosenInfinitePlaceAbove (L := L) v).IsRamified K) :
    (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v).map
        (Complex.conjAe.restrictScalars ℚ).toAlgHom =
      infinitePlaceComplexificationOverfield
        (K := K) (L := L) v
GlobalClassFieldTheory.Reciprocity.ramifiedInfinitePlaceOverfieldConjugation

Complex conjugation restricted to the actual overfield L(i).

Source context 9 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
def ramifiedInfinitePlaceOverfieldConjugation
    (v : InfinitePlace K)
    (hRamified :
      (chosenInfinitePlaceAbove (L := L) v).IsRamified K) :
    infinitePlaceComplexificationOverfield
          (K := K) (L := L) v ≃ₐ[ℚ]
      infinitePlaceComplexificationOverfield
          (K := K) (L := L) v
GlobalClassFieldTheory.Reciprocity.ramifiedInfinitePlaceOverfieldConjugation_apply

The restricted overfield automorphism acts by ambient complex conjugation.

Source context 10 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
omit [NumberField K] [FiniteDimensional K L] in
theorem ramifiedInfinitePlaceOverfieldConjugation_apply
    (v : InfinitePlace K)
    (hRamified :
      (chosenInfinitePlaceAbove (L := L) v).IsRamified K)
    (z :
      infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :
    (ramifiedInfinitePlaceOverfieldConjugation
        (K := K) (L := L) v hRamified z : ℂ) =
      star (z : ℂ)
GlobalClassFieldTheory.Reciprocity.ramifiedInfinitePlaceOverfieldConjugation_sq

The restricted overfield complex conjugation is an involution.

Source context 10 commands

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

open scoped IsMulCommutative
open NumberField
noncomputable section
namespace GlobalClassFieldTheory
namespace Reciprocity
section ComplexConjugationOverextension
variable
    {K L : Type}
    [Field K]
    [Field L] [NumberField L] [Algebra K L]
variable
    [NumberField K]
    [FiniteDimensional K L] [IsAbelianGalois K L]
@[reducible]
noncomputable local instance
    infinitePlaceComplexificationOverfieldRationalAlgebra
    (v : InfinitePlace K) :
    Algebra ℚ
      (infinitePlaceComplexificationOverfield
        (K := K) (L := L) v) :=
  (infinitePlaceComplexificationOverfield
    (K := K) (L := L) v).algebra'
omit [NumberField K] [FiniteDimensional K L] in
theorem ramifiedInfinitePlaceOverfieldConjugation_sq
    (v : InfinitePlace K)
    (hRamified :
      (chosenInfinitePlaceAbove (L := L) v).IsRamified K) :
    ramifiedInfinitePlaceOverfieldConjugation
          (K := K) (L := L) v hRamified *
        ramifiedInfinitePlaceOverfieldConjugation
          (K := K) (L := L) v hRamified =
      1