Module

IdealRadicalCyclotomicModule.lean

Nyll.SawinTotallyRealTowers.UnramifiedProPRelationRank.Radical.IdealRadicalCyclotomicModule
7 declarations indexed from sourceView source ↗

The cyclotomic ideal radical as a ZMod p-module

The ideal radical over F maps onto the restricted radical generated after adjoining a primitive p-th root of unity. This file makes that quotient and the quotient map linear, then dualizes the surjection to a canonical injection into the dual of the original ideal radical.

All module structures are kept inside explicit definitions; no noncanonical global instance is installed.

Declarations

ClassFieldTower.Martinet.Shafarevich.idealRadicalCyclotomicModPModule

The canonical ZMod p-module structure on the cyclotomic restricted ideal-radical quotient.

Source context 6 commands

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

open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open KummerTheory
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) [Fact p.Prime]
def idealRadicalCyclotomicModPModule :
    Module (ZMod p)
      (Additive
        (RestrictedRadicalQuotient (p.toPNat (Fact.out : p.Prime).pos)
          (idealRadicalCyclotomicKummerSubgroup F p Fact.out)))
ClassFieldTower.Martinet.Shafarevich.idealRadicalCyclotomicModP

The cyclotomic restricted ideal radical as a ZMod p-module object.

Source context 6 commands

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

open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open KummerTheory
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) [Fact p.Prime]
def idealRadicalCyclotomicModP : ModuleCat (ZMod p)
ClassFieldTower.Martinet.Shafarevich.idealRadicalQuotientToCyclotomicLinearMap

The base-change map on ideal radicals, viewed linearly over ZMod p.

Source context 6 commands

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

open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open KummerTheory
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) [Fact p.Prime]
def idealRadicalQuotientToCyclotomicLinearMap :
    idealPowerRadicalModP F p →ₗ[ZMod p]
      idealRadicalCyclotomicModP F p
ClassFieldTower.Martinet.Shafarevich.idealRadicalQuotientToCyclotomicLinearMap_surjective

The linearized base-change map is onto.

Source context 6 commands

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

open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open KummerTheory
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) [Fact p.Prime]
theorem idealRadicalQuotientToCyclotomicLinearMap_surjective :
    Function.Surjective
      (idealRadicalQuotientToCyclotomicLinearMap F p)
ClassFieldTower.Martinet.Shafarevich.idealRadicalCyclotomicDualInjection

Dualizing the cyclotomic quotient map gives a canonical linear map into the dual of the base-field ideal radical.

Source context 6 commands

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

open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open KummerTheory
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) [Fact p.Prime]
def idealRadicalCyclotomicDualInjection :
    Module.Dual (ZMod p) (idealRadicalCyclotomicModP F p) →ₗ[ZMod p]
      Module.Dual (ZMod p) (idealPowerRadicalModP F p)
ClassFieldTower.Martinet.Shafarevich.idealRadicalCyclotomicDualInjection_injective

The dualized map is injective because the ideal-radical base-change map is surjective.

Source context 6 commands

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

open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open KummerTheory
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) [Fact p.Prime]
theorem idealRadicalCyclotomicDualInjection_injective :
    Function.Injective (idealRadicalCyclotomicDualInjection F p)
ClassFieldTower.Martinet.Shafarevich.idealRadicalCyclotomicModP_finiteDimensional

The cyclotomic restricted ideal radical is finite-dimensional.

Source context 6 commands

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

open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open KummerTheory
variable (F : Type*) [Field F] [NumberField F]
variable (p : ℕ) [Fact p.Prime]
theorem idealRadicalCyclotomicModP_finiteDimensional :
    FiniteDimensional (ZMod p) (idealRadicalCyclotomicModP F p)