Module

CyclotomicAbsoluteH2Vanishing.lean

Nyll.SawinTotallyRealTowers.UnramifiedProPRelationRank.RelationRank.CyclotomicAbsoluteH2Vanishing
7 declarations indexed from sourceView source ↗

Absolute inflation vanishes over every number field

The actual cyclotomic base change of an unramified arithmetic stage is mapped into the standard cyclotomic algebraic closure using exactly the equivalence underlying finite-extension absolute restriction. Evaluation on field elements proves the restriction square. The mapped stage has zero absolute H², and prime-to-p cyclotomic restriction is injective.

Thus no primitive-root hypothesis remains. Finite-stage realization then shows that every continuous degree-two class of the maximal everywhere- unramified pro-p group vanishes on the absolute Galois group, for odd p. Only two local proposition-valued instances name the finite cyclotomic base and its number-field certificate; no comparison assumption is used.

Declarations

ClassFieldTower.Martinet.Shafarevich.cyclotomicVanishingBaseFinite
Source context 9 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Martinet ClassFieldTower.ProP ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
variable (F : Type) [Field F] [NumberField F]
variable (n : ℕ+) [Fact (n : ℕ).Prime] (hpOdd : Odd (n : ℕ))
variable (U : OpenNormalSubgroup (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ)))
local notation "Cyclo" => IdealRadicalCyclotomicBase F (n : ℕ) (Fact.out : Nat.Prime (n : ℕ))
local notation "OriginalStage" => FiniteEverywhereUnramifiedProPExtension.field
  (openNormalArithmeticStage F (n : ℕ) hpOdd U)
instance cyclotomicVanishingBaseFinite : FiniteDimensional F Cyclo
ClassFieldTower.Martinet.Shafarevich.cyclotomicVanishingBaseNumber
Source context 10 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Martinet ClassFieldTower.ProP ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
variable (F : Type) [Field F] [NumberField F]
variable (n : ℕ+) [Fact (n : ℕ).Prime] (hpOdd : Odd (n : ℕ))
variable (U : OpenNormalSubgroup (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ)))
local notation "Cyclo" => IdealRadicalCyclotomicBase F (n : ℕ) (Fact.out : Nat.Prime (n : ℕ))
local notation "OriginalStage" => FiniteEverywhereUnramifiedProPExtension.field
  (openNormalArithmeticStage F (n : ℕ) hpOdd U)
local instance cyclotomicVanishingBaseFinite : FiniteDimensional F Cyclo :=
  finiteDimensional_idealRadicalCyclotomicBase F (n : ℕ) Fact.out
instance cyclotomicVanishingBaseNumber : NumberField Cyclo
ClassFieldTower.Martinet.Shafarevich.cyclotomicArithmeticStageRestrictionContinuous

Actual finite restriction from the synchronized cyclotomic stage, viewed as a continuous homomorphism between finite Galois groups.

Source context 13 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Martinet ClassFieldTower.ProP ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
variable (F : Type) [Field F] [NumberField F]
variable (n : ℕ+) [Fact (n : ℕ).Prime] (hpOdd : Odd (n : ℕ))
variable (U : OpenNormalSubgroup (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ)))
local notation "Cyclo" => IdealRadicalCyclotomicBase F (n : ℕ) (Fact.out : Nat.Prime (n : ℕ))
local notation "OriginalStage" => FiniteEverywhereUnramifiedProPExtension.field
  (openNormalArithmeticStage F (n : ℕ) hpOdd U)
local instance cyclotomicVanishingBaseFinite : FiniteDimensional F Cyclo :=
  finiteDimensional_idealRadicalCyclotomicBase F (n : ℕ) Fact.out
local instance cyclotomicVanishingBaseNumber : NumberField Cyclo :=
  NumberField.of_module_finite F Cyclo
local notation "closureEquiv" => finiteIntermediateAbsoluteClosureEquiv F Cyclo
local notation "MappedStage" =>
  cyclotomicArithmeticStageMappedExtension F (n : ℕ) hpOdd U closureEquiv
def cyclotomicArithmeticStageRestrictionContinuous :
    Gal((MappedStage).field/Cyclo) →ₜ* Gal(OriginalStage/F) where
  toMonoidHom := cyclotomicArithmeticStageMappedRestriction F (n : ℕ) hpOdd U closureEquiv
  continuous_toFun := continuous_of_discreteTopology
ClassFieldTower.Martinet.Shafarevich.cyclotomicArithmeticStageAbsoluteRestriction_factor

The finite restriction square commutes with the actual absolute Galois inclusion, using the same closure equivalence on both sides.

Source context 13 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Martinet ClassFieldTower.ProP ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
variable (F : Type) [Field F] [NumberField F]
variable (n : ℕ+) [Fact (n : ℕ).Prime] (hpOdd : Odd (n : ℕ))
variable (U : OpenNormalSubgroup (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ)))
local notation "Cyclo" => IdealRadicalCyclotomicBase F (n : ℕ) (Fact.out : Nat.Prime (n : ℕ))
local notation "OriginalStage" => FiniteEverywhereUnramifiedProPExtension.field
  (openNormalArithmeticStage F (n : ℕ) hpOdd U)
local instance cyclotomicVanishingBaseFinite : FiniteDimensional F Cyclo :=
  finiteDimensional_idealRadicalCyclotomicBase F (n : ℕ) Fact.out
local instance cyclotomicVanishingBaseNumber : NumberField Cyclo :=
  NumberField.of_module_finite F Cyclo
local notation "closureEquiv" => finiteIntermediateAbsoluteClosureEquiv F Cyclo
local notation "MappedStage" =>
  cyclotomicArithmeticStageMappedExtension F (n : ℕ) hpOdd U closureEquiv
theorem cyclotomicArithmeticStageAbsoluteRestriction_factor :
    (cyclotomicArithmeticStageRestrictionContinuous F n hpOdd U).comp
      (finiteUnramifiedExtensionAbsoluteRestriction Cyclo n MappedStage) =
    (openNormalArithmeticStageAbsoluteRestriction F n hpOdd U).comp
      (cyclotomicAbsoluteGaloisInclusion F (n : ℕ))
ClassFieldTower.Martinet.Shafarevich.openNormalArithmeticStage_absoluteH2Map_eq_zero_of_odd

Every finite unramified arithmetic-stage H² class vanishes on the absolute Galois group, without assuming that the base contains mu_p.

Source context 13 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Martinet ClassFieldTower.ProP ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
variable (F : Type) [Field F] [NumberField F]
variable (n : ℕ+) [Fact (n : ℕ).Prime] (hpOdd : Odd (n : ℕ))
variable (U : OpenNormalSubgroup (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ)))
local notation "Cyclo" => IdealRadicalCyclotomicBase F (n : ℕ) (Fact.out : Nat.Prime (n : ℕ))
local notation "OriginalStage" => FiniteEverywhereUnramifiedProPExtension.field
  (openNormalArithmeticStage F (n : ℕ) hpOdd U)
local instance cyclotomicVanishingBaseFinite : FiniteDimensional F Cyclo :=
  finiteDimensional_idealRadicalCyclotomicBase F (n : ℕ) Fact.out
local instance cyclotomicVanishingBaseNumber : NumberField Cyclo :=
  NumberField.of_module_finite F Cyclo
local notation "closureEquiv" => finiteIntermediateAbsoluteClosureEquiv F Cyclo
local notation "MappedStage" =>
  cyclotomicArithmeticStageMappedExtension F (n : ℕ) hpOdd U closureEquiv
theorem openNormalArithmeticStage_absoluteH2Map_eq_zero_of_odd
    (x : continuousCohomologyZModPLifted (n : ℕ) Gal(OriginalStage/F) 2) :
    (continuousCohomologyZModPMapLifted (n : ℕ)
      (openNormalArithmeticStageAbsoluteRestriction F n hpOdd U) 2).hom x = 0
ClassFieldTower.Martinet.Shafarevich.openNormalQuotient_absoluteH2Inflation_eq_zero_of_odd

Absolute inflation kills a finite open-normal quotient H² class for every number field and odd p.

Source context 14 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Martinet ClassFieldTower.ProP ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
variable (F : Type) [Field F] [NumberField F]
variable (n : ℕ+) [Fact (n : ℕ).Prime] (hpOdd : Odd (n : ℕ))
variable (U : OpenNormalSubgroup (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ)))
local notation "Cyclo" => IdealRadicalCyclotomicBase F (n : ℕ) (Fact.out : Nat.Prime (n : ℕ))
local notation "OriginalStage" => FiniteEverywhereUnramifiedProPExtension.field
  (openNormalArithmeticStage F (n : ℕ) hpOdd U)
local instance cyclotomicVanishingBaseFinite : FiniteDimensional F Cyclo :=
  finiteDimensional_idealRadicalCyclotomicBase F (n : ℕ) Fact.out
local instance cyclotomicVanishingBaseNumber : NumberField Cyclo :=
  NumberField.of_module_finite F Cyclo
local notation "closureEquiv" => finiteIntermediateAbsoluteClosureEquiv F Cyclo
local notation "MappedStage" =>
  cyclotomicArithmeticStageMappedExtension F (n : ℕ) hpOdd U closureEquiv
include hpOdd
theorem openNormalQuotient_absoluteH2Inflation_eq_zero_of_odd
    (x : continuousCohomologyZModPLifted (n : ℕ)
      (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ) ⧸
        (U : Subgroup (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ)))) 2) :
    (continuousCohomologyZModPMapLifted (n : ℕ)
      (absoluteToMaxEverywhereUnramifiedProP F (n : ℕ)) 2).hom
        ((continuousCohomologyZModPMapLifted (n : ℕ)
          (OpenNormalSubgroup.quotientProj U) 2).hom x) = 0
ClassFieldTower.Martinet.Shafarevich.absoluteUnramifiedH2Inflation_eq_zero

Every unramified pro-p degree-two class has zero absolute inflation over every number field, for odd p.

Source context 15 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Martinet ClassFieldTower.ProP ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
variable (F : Type) [Field F] [NumberField F]
variable (n : ℕ+) [Fact (n : ℕ).Prime] (hpOdd : Odd (n : ℕ))
variable (U : OpenNormalSubgroup (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ)))
local notation "Cyclo" => IdealRadicalCyclotomicBase F (n : ℕ) (Fact.out : Nat.Prime (n : ℕ))
local notation "OriginalStage" => FiniteEverywhereUnramifiedProPExtension.field
  (openNormalArithmeticStage F (n : ℕ) hpOdd U)
local instance cyclotomicVanishingBaseFinite : FiniteDimensional F Cyclo :=
  finiteDimensional_idealRadicalCyclotomicBase F (n : ℕ) Fact.out
local instance cyclotomicVanishingBaseNumber : NumberField Cyclo :=
  NumberField.of_module_finite F Cyclo
local notation "closureEquiv" => finiteIntermediateAbsoluteClosureEquiv F Cyclo
local notation "MappedStage" =>
  cyclotomicArithmeticStageMappedExtension F (n : ℕ) hpOdd U closureEquiv
include hpOdd
omit U in
theorem absoluteUnramifiedH2Inflation_eq_zero
    (x : continuousCohomologyZModPLifted (n : ℕ)
      (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ)) 2) :
    (continuousCohomologyZModPMapLifted (n : ℕ)
      (absoluteToMaxEverywhereUnramifiedProP F (n : ℕ)) 2).hom x = 0