Module

FiniteStageTransgressionQuotient.lean

Nyll.GaloisCohomology.ProP.FiniteStageTransgressionQuotient
6 declarations indexed from sourceView source ↗

Quotient presentation of finite-stage transgression

At a finite quotient stage, invariant characters modulo restrictions of continuous degree-one characters identify with the range of finite transgression.

Declarations

ClassFieldTower.ProP.finiteStageQuotientZModTopology
Source context 8 commands

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

namespace ClassFieldTower.ProP
open ProCGroups ProCGroups.ProC
open ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {F : Type u} [Group F] [TopologicalSpace F] [IsTopologicalGroup F]
variable [CompactSpace F]
instance finiteStageQuotientZModTopology : TopologicalSpace (ZMod p)
ClassFieldTower.ProP.finiteStageQuotientZModDiscrete
Source context 9 commands

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

namespace ClassFieldTower.ProP
open ProCGroups ProCGroups.ProC
open ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {F : Type u} [Group F] [TopologicalSpace F] [IsTopologicalGroup F]
variable [CompactSpace F]
local instance finiteStageQuotientZModTopology : TopologicalSpace (ZMod p) := ⊥
instance finiteStageQuotientZModDiscrete : DiscreteTopology (ZMod p)
ClassFieldTower.ProP.finiteStageQuotientContinuousH1Module
Source context 10 commands

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

namespace ClassFieldTower.ProP
open ProCGroups ProCGroups.ProC
open ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {F : Type u} [Group F] [TopologicalSpace F] [IsTopologicalGroup F]
variable [CompactSpace F]
local instance finiteStageQuotientZModTopology : TopologicalSpace (ZMod p) := ⊥
local instance finiteStageQuotientZModDiscrete : DiscreteTopology (ZMod p) :=
  discreteTopology_bot _
instance finiteStageQuotientContinuousH1Module
    (U : OpenNormalSubgroupInClass (FiniteGroupClass.pGroup p) F) :
    Module (ZMod p)
      (ContinuousH1ZMod (p := p) (G := F ⧸ (U.1 : Subgroup F)))
ClassFieldTower.ProP.finiteStageContinuousCharacterQuotientEquivTransgressionRange

Invariant finite-stage characters modulo continuous ambient restrictions are linearly equivalent to the finite-transgression range.

Source context 11 commands

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

namespace ClassFieldTower.ProP
open ProCGroups ProCGroups.ProC
open ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {F : Type u} [Group F] [TopologicalSpace F] [IsTopologicalGroup F]
variable [CompactSpace F]
local instance finiteStageQuotientZModTopology : TopologicalSpace (ZMod p) := ⊥
local instance finiteStageQuotientZModDiscrete : DiscreteTopology (ZMod p) :=
  discreteTopology_bot _
local instance finiteStageQuotientContinuousH1Module
    (U : OpenNormalSubgroupInClass (FiniteGroupClass.pGroup p) F) :
    Module (ZMod p)
      (ContinuousH1ZMod (p := p) (G := F ⧸ (U.1 : Subgroup F))) :=
  continuousH1ZModModule
def finiteStageContinuousCharacterQuotientEquivTransgressionRange
    (R : ClosedSubgroup F) [R.Normal]
    (U : OpenNormalSubgroupInClass (FiniteGroupClass.pGroup p) F) :
    (InvariantFiniteCharacter (p := p) (finiteStageImage R U) ⧸
        LinearMap.range (finiteStageContinuousCharacterRestrictionLinearMap R U)) ≃ₗ[ZMod p]
      LinearMap.range
        (finiteTransgressionLinearMap (p := p) (finiteStageImage R U))
ClassFieldTower.ProP.finiteStageContinuousCharacterQuotientEquivTransgressionRange_apply_mk
Source context 11 commands

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

namespace ClassFieldTower.ProP
open ProCGroups ProCGroups.ProC
open ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {F : Type u} [Group F] [TopologicalSpace F] [IsTopologicalGroup F]
variable [CompactSpace F]
local instance finiteStageQuotientZModTopology : TopologicalSpace (ZMod p) := ⊥
local instance finiteStageQuotientZModDiscrete : DiscreteTopology (ZMod p) :=
  discreteTopology_bot _
local instance finiteStageQuotientContinuousH1Module
    (U : OpenNormalSubgroupInClass (FiniteGroupClass.pGroup p) F) :
    Module (ZMod p)
      (ContinuousH1ZMod (p := p) (G := F ⧸ (U.1 : Subgroup F))) :=
  continuousH1ZModModule
theorem finiteStageContinuousCharacterQuotientEquivTransgressionRange_apply_mk
    (R : ClosedSubgroup F) [R.Normal]
    (U : OpenNormalSubgroupInClass (FiniteGroupClass.pGroup p) F)
    (χ : InvariantFiniteCharacter (p := p) (finiteStageImage R U)) :
    finiteStageContinuousCharacterQuotientEquivTransgressionRange R U
        (Submodule.Quotient.mk χ) =
      ⟨finiteTransgressionLinearMap (finiteStageImage R U) χ,
        LinearMap.mem_range_self
          (finiteTransgressionLinearMap (finiteStageImage R U)) χ⟩
ClassFieldTower.ProP.finrank_finiteStageContinuousCharacterQuotient_eq_transgressionRange

The continuous-character quotient and the finite-stage transgression range have equal ZMod p-dimension.

Source context 11 commands

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

namespace ClassFieldTower.ProP
open ProCGroups ProCGroups.ProC
open ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {F : Type u} [Group F] [TopologicalSpace F] [IsTopologicalGroup F]
variable [CompactSpace F]
local instance finiteStageQuotientZModTopology : TopologicalSpace (ZMod p) := ⊥
local instance finiteStageQuotientZModDiscrete : DiscreteTopology (ZMod p) :=
  discreteTopology_bot _
local instance finiteStageQuotientContinuousH1Module
    (U : OpenNormalSubgroupInClass (FiniteGroupClass.pGroup p) F) :
    Module (ZMod p)
      (ContinuousH1ZMod (p := p) (G := F ⧸ (U.1 : Subgroup F))) :=
  continuousH1ZModModule
theorem finrank_finiteStageContinuousCharacterQuotient_eq_transgressionRange
    (R : ClosedSubgroup F) [R.Normal]
    (U : OpenNormalSubgroupInClass (FiniteGroupClass.pGroup p) F) :
    Module.finrank (ZMod p)
        (InvariantFiniteCharacter (p := p) (finiteStageImage R U) ⧸
          LinearMap.range (finiteStageContinuousCharacterRestrictionLinearMap R U)) =
      Module.finrank (ZMod p)
        (LinearMap.range
          (finiteTransgressionLinearMap (p := p) (finiteStageImage R U)))