Module

OpenNormalArithmeticStage.lean

Nyll.SawinTotallyRealTowers.UnramifiedProPRelationRank.RelationRank.OpenNormalArithmeticStage
6 declarations indexed from sourceView source ↗

Arithmetic fields attached to open normal quotients

An open normal quotient of the maximal everywhere-unramified pro-p Galois group is realized by the Galois group of a concrete finite everywhere-unramified p-extension. This is the finite-stage arithmetic bridge used before introducing any cohomological local--global map.

Declarations

ClassFieldTower.Martinet.Shafarevich.openNormalClosedSubgroup
Source context 8 commands

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

open scoped NumberField
noncomputable section
universe u
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Martinet
open ProCGroups
variable (F : Type u) [Field F] [NumberField F]
variable (p : ℕ) [Fact p.Prime]
def openNormalClosedSubgroup
    (U : OpenNormalSubgroup
      (MaxEverywhereUnramifiedProPGaloisGroup F p)) :
    ClosedSubgroup (MaxEverywhereUnramifiedProPGaloisGroup F p)
ClassFieldTower.Martinet.Shafarevich.openNormalFixedFieldInMaximal
Source context 8 commands

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

open scoped NumberField
noncomputable section
universe u
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Martinet
open ProCGroups
variable (F : Type u) [Field F] [NumberField F]
variable (p : ℕ) [Fact p.Prime]
def openNormalFixedFieldInMaximal
    (U : OpenNormalSubgroup
      (MaxEverywhereUnramifiedProPGaloisGroup F p)) :
    IntermediateField F (maximalEverywhereUnramifiedProP F p)
ClassFieldTower.Martinet.Shafarevich.openNormalFixedField

The fixed field of an open normal subgroup, transported from the maximal compositum into the chosen algebraic closure.

Source context 8 commands

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

open scoped NumberField
noncomputable section
universe u
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Martinet
open ProCGroups
variable (F : Type u) [Field F] [NumberField F]
variable (p : ℕ) [Fact p.Prime]
def openNormalFixedField
    (U : OpenNormalSubgroup
      (MaxEverywhereUnramifiedProPGaloisGroup F p)) :
    IntermediateField F (AlgebraicClosure F)
ClassFieldTower.Martinet.Shafarevich.openNormalArithmeticStage

For odd p, the fixed field of an open normal subgroup is a bundled finite Galois everywhere-unramified p-extension.

Source context 8 commands

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

open scoped NumberField
noncomputable section
universe u
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Martinet
open ProCGroups
variable (F : Type u) [Field F] [NumberField F]
variable (p : ℕ) [Fact p.Prime]
def openNormalArithmeticStage
    (hpOdd : Odd p)
    (U : OpenNormalSubgroup
      (MaxEverywhereUnramifiedProPGaloisGroup F p)) :
    FiniteEverywhereUnramifiedProPExtension F p
ClassFieldTower.Martinet.Shafarevich.openNormalArithmeticStage_field
Source context 8 commands

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

open scoped NumberField
noncomputable section
universe u
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Martinet
open ProCGroups
variable (F : Type u) [Field F] [NumberField F]
variable (p : ℕ) [Fact p.Prime]
theorem openNormalArithmeticStage_field
    (hpOdd : Odd p)
    (U : OpenNormalSubgroup
      (MaxEverywhereUnramifiedProPGaloisGroup F p)) :
    (openNormalArithmeticStage F p hpOdd U).field =
      openNormalFixedField F p U
ClassFieldTower.Martinet.Shafarevich.openNormalQuotientEquivArithmeticStageGalois

The quotient by an open normal subgroup is the Galois group of its concrete finite everywhere-unramified arithmetic stage.

Source context 8 commands

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

open scoped NumberField
noncomputable section
universe u
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Martinet
open ProCGroups
variable (F : Type u) [Field F] [NumberField F]
variable (p : ℕ) [Fact p.Prime]
def openNormalQuotientEquivArithmeticStageGalois
    (hpOdd : Odd p)
    (U : OpenNormalSubgroup
      (MaxEverywhereUnramifiedProPGaloisGroup F p)) :
    (MaxEverywhereUnramifiedProPGaloisGroup F p ⧸
        (U : Subgroup
          (MaxEverywhereUnramifiedProPGaloisGroup F p))) ≃*
      ((openNormalArithmeticStage F p hpOdd U).field ≃ₐ[F]
        (openNormalArithmeticStage F p hpOdd U).field)