Module

IdealRadicalCyclotomicBase.lean

Nyll.SawinTotallyRealTowers.UnramifiedProPRelationRank.Radical.IdealRadicalCyclotomicBase
12 declarations indexed from sourceView source ↗

The ideal radical over a cyclotomic base

For a number field F and a prime p, this file chooses a primitive p-th root in AlgebraicClosure F, names F(μ_p), and maps the empty-support ideal p-power radical into an admissible Kummer subgroup over that cyclotomic base. Its restricted radical quotient is finite, by a source-proved surjection from the base-field ideal radical quotient.

Declarations

ClassFieldTower.Martinet.Shafarevich.idealRadicalPrimitiveRoot

A chosen primitive p-th root of unity in the fixed algebraic closure.

Source context 7 commands

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

open scoped NumberField
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField
open KummerTheory
noncomputable section
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) (hp : p.Prime)
def idealRadicalPrimitiveRoot : AlgebraicClosure F
ClassFieldTower.Martinet.Shafarevich.idealRadicalPrimitiveRoot_isPrimitiveRoot
Source context 7 commands

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

open scoped NumberField
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField
open KummerTheory
noncomputable section
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) (hp : p.Prime)
theorem idealRadicalPrimitiveRoot_isPrimitiveRoot :
    IsPrimitiveRoot (idealRadicalPrimitiveRoot F p hp) p
ClassFieldTower.Martinet.Shafarevich.IdealRadicalCyclotomicBase

The cyclotomic base F(μ_p) inside AlgebraicClosure F.

Source context 7 commands

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

open scoped NumberField
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField
open KummerTheory
noncomputable section
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) (hp : p.Prime)
def IdealRadicalCyclotomicBase :
    IntermediateField F (AlgebraicClosure F)
ClassFieldTower.Martinet.Shafarevich.finiteDimensional_idealRadicalCyclotomicBase
Source context 7 commands

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

open scoped NumberField
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField
open KummerTheory
noncomputable section
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) (hp : p.Prime)
theorem finiteDimensional_idealRadicalCyclotomicBase :
    FiniteDimensional F (IdealRadicalCyclotomicBase F p hp)
ClassFieldTower.Martinet.Shafarevich.idealRadicalCyclotomicBase_primitiveRoots_nonempty

The named cyclotomic base contains a primitive p-th root.

Source context 7 commands

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

open scoped NumberField
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField
open KummerTheory
noncomputable section
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) (hp : p.Prime)
theorem idealRadicalCyclotomicBase_primitiveRoots_nonempty :
    (primitiveRoots p (IdealRadicalCyclotomicBase F p hp)).Nonempty
ClassFieldTower.Martinet.Shafarevich.idealRadicalToCyclotomicBase

Map the base-field ideal radical into the unit group of F(μ_p).

Source context 7 commands

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

open scoped NumberField
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField
open KummerTheory
noncomputable section
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) (hp : p.Prime)
def idealRadicalToCyclotomicBase :
    (idealNthPowerRadicalKummerSubgroup F (p.toPNat hp.pos)).1 →*
      (IdealRadicalCyclotomicBase F p hp)ˣ
ClassFieldTower.Martinet.Shafarevich.idealRadicalCyclotomicKummerSubgroup

The Kummer subgroup over F(μ_p) generated by the mapped ideal radical and all ambient p-th powers.

Source context 7 commands

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

open scoped NumberField
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField
open KummerTheory
noncomputable section
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) (hp : p.Prime)
def idealRadicalCyclotomicKummerSubgroup :
    KummerSubgroup (IdealRadicalCyclotomicBase F p hp) (p.toPNat hp.pos)
ClassFieldTower.Martinet.Shafarevich.idealRadicalToCyclotomicKummerSubgroup

The base-field ideal radical, with codomain restricted to the cyclotomic Kummer subgroup.

Source context 7 commands

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

open scoped NumberField
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField
open KummerTheory
noncomputable section
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) (hp : p.Prime)
def idealRadicalToCyclotomicKummerSubgroup :
    (idealNthPowerRadicalKummerSubgroup F (p.toPNat hp.pos)).1 →*
      (idealRadicalCyclotomicKummerSubgroup F p hp).1
ClassFieldTower.Martinet.Shafarevich.idealRadicalToCyclotomicQuotientRaw
Source context 7 commands

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

open scoped NumberField
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField
open KummerTheory
noncomputable section
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) (hp : p.Prime)
def idealRadicalToCyclotomicQuotientRaw :
    (idealNthPowerRadicalKummerSubgroup F (p.toPNat hp.pos)).1 →*
      RestrictedRadicalQuotient (p.toPNat hp.pos)
        (idealRadicalCyclotomicKummerSubgroup F p hp)
ClassFieldTower.Martinet.Shafarevich.idealRadicalQuotientToCyclotomicQuotient

The induced map from the base-field ideal radical quotient to the cyclotomic Kummer quotient.

Source context 7 commands

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

open scoped NumberField
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField
open KummerTheory
noncomputable section
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) (hp : p.Prime)
def idealRadicalQuotientToCyclotomicQuotient :
    IdealNthPowerRadicalQuotient F (p.toPNat hp.pos) →*
      RestrictedRadicalQuotient (p.toPNat hp.pos)
        (idealRadicalCyclotomicKummerSubgroup F p hp)
ClassFieldTower.Martinet.Shafarevich.idealRadicalQuotientToCyclotomicQuotient_surjective

Every cyclotomic Kummer class is represented by a mapped base-field ideal radical class.

Source context 7 commands

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

open scoped NumberField
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField
open KummerTheory
noncomputable section
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) (hp : p.Prime)
theorem idealRadicalQuotientToCyclotomicQuotient_surjective :
    Function.Surjective (idealRadicalQuotientToCyclotomicQuotient F p hp)
ClassFieldTower.Martinet.Shafarevich.finite_idealRadicalCyclotomicRestrictedQuotient

The cyclotomic Kummer quotient generated by the ideal radical is finite.

Source context 7 commands

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

open scoped NumberField
namespace ClassFieldTower.Martinet.Shafarevich
open NumberField
open KummerTheory
noncomputable section
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) (hp : p.Prime)
theorem finite_idealRadicalCyclotomicRestrictedQuotient :
    Finite (RestrictedRadicalQuotient (p.toPNat hp.pos)
      (idealRadicalCyclotomicKummerSubgroup F p hp))