Module

ArithmeticStageH2RadicalKernel.lean

Nyll.SawinTotallyRealTowers.UnramifiedProPRelationRank.RelationRank.ArithmeticStageH2RadicalKernel
3 declarations indexed from sourceView source ↗

The actual radical functional detects stage inflation

A zero radical functional supplies a global character agreeing with the chosen lift's inertia defects. Correcting the lift by this character kills every finite inertia group. The actual maximal-unramified factor therefore lifts the stage quotient, forcing its inflated degree-two class to vanish.

Declarations

ClassFieldTower.Martinet.Shafarevich.arithmeticRadicalKernelTopology
Source context 10 commands

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

open NumberField IsDedekindDomain
open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Cohomology ClassFieldTower.ProP ClassFieldTower.Martinet ProCGroups
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 "StageQuotient" => MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ) ⧸
  (U : Subgroup (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ)))
local notation "StageH2" => continuousCohomologyZModPLifted (n : ℕ) StageQuotient 2
instance arithmeticRadicalKernelTopology : TopologicalSpace (ZMod (n : ℕ))
ClassFieldTower.Martinet.Shafarevich.arithmeticRadicalKernelDiscrete
Source context 11 commands

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

open NumberField IsDedekindDomain
open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Cohomology ClassFieldTower.ProP ClassFieldTower.Martinet ProCGroups
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 "StageQuotient" => MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ) ⧸
  (U : Subgroup (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ)))
local notation "StageH2" => continuousCohomologyZModPLifted (n : ℕ) StageQuotient 2
local instance arithmeticRadicalKernelTopology : TopologicalSpace (ZMod (n : ℕ)) := ⊥
instance arithmeticRadicalKernelDiscrete : DiscreteTopology (ZMod (n : ℕ))
ClassFieldTower.Martinet.Shafarevich.arithmeticStageH2RadicalFunctional_eq_zero_imp_inflation_eq_zero

Vanishing of the actual ideal-radical functional forces the stage class to vanish in the maximal everywhere-unramified pro-p group.

Source context 12 commands

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

open NumberField IsDedekindDomain
open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.Cohomology ClassFieldTower.ProP ClassFieldTower.Martinet ProCGroups
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 "StageQuotient" => MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ) ⧸
  (U : Subgroup (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ)))
local notation "StageH2" => continuousCohomologyZModPLifted (n : ℕ) StageQuotient 2
local instance arithmeticRadicalKernelTopology : TopologicalSpace (ZMod (n : ℕ)) := ⊥
local instance arithmeticRadicalKernelDiscrete : DiscreteTopology (ZMod (n : ℕ)) :=
  discreteTopology_bot _
theorem arithmeticStageH2RadicalFunctional_eq_zero_imp_inflation_eq_zero
    (x : StageH2) (hx : arithmeticStageH2RadicalFunctional F n hpOdd U x = 0) :
    (continuousCohomologyZModPMapLifted (n : ℕ)
      (quotientProjection (U : Subgroup
        (MaxEverywhereUnramifiedProPGaloisGroup F (n : ℕ)))) 2).hom x = 0