Module

ContinuousLowDegreeFiveTermExact.lean

Nyll.GaloisCohomology.ProP.ContinuousLowDegreeFiveTermExact
2 declarations indexed from sourceView source ↗

Continuous low-degree five-term exact sequence

The three kernel--range identities for inflation, restriction, and transgression assemble into the continuous low-degree five-term sequence with trivial ZMod p coefficients.

Declarations

ClassFieldTower.Cohomology.continuousFiveTermH1Module
Source context 8 commands

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

open scoped Topology
namespace ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
open ClassFieldTower.ProP
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
instance continuousFiveTermH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H))
ClassFieldTower.Cohomology.continuousLowDegreeFiveTerm_exact

Exactness at the three middle terms of the continuous low-degree sequence

H¹(G/U) → H¹(G) → H¹(U)ᴳ → H²(G/U) → H²(G).

Source context 9 commands

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

open scoped Topology
namespace ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
open ClassFieldTower.ProP
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance continuousFiveTermH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H)) :=
  continuousH1ZModModule
theorem continuousLowDegreeFiveTerm_exact
    (U : OpenNormalSubgroupInClass (FiniteGroupClass.pGroup p) G) :
    Function.Exact
        (continuousH1InflationLinearMap U)
        (continuousCharacterRestrictionLinearMap U) ∧
      Function.Exact
        (continuousCharacterRestrictionLinearMap U)
        (continuousTransgressionLinearMap U) ∧
      Function.Exact
        (continuousTransgressionLinearMap U)
        (degreeTwoInflationLinearMap U)