Module

ContinuousH1CupCochain.lean

Nyll.GaloisCohomology.ProP.ContinuousH1CupCochain
9 declarations indexed from sourceView source ↗

The continuous cup product of two trivial mod-p characters

For continuous additive ZMod p-characters, the canonical homogeneous representatives give the degree-two cochain

(g, h, k) ↦ χ(g⁻¹h) * ψ(h⁻¹k).

This file constructs that cochain directly and proves its cocycle equation. No choice of cocycle representatives is involved.

Declarations

ClassFieldTower.Cohomology.continuousH1CupContinuousSMulULiftZMod
Source context 8 commands

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

open CategoryTheory TopRep ContRepresentation
open ClassFieldTower.ProP
open scoped Topology
namespace ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
instance continuousH1CupContinuousSMulULiftZMod :
    ContinuousSMul (ZMod p) (ULift.{u} (ZMod p))
ClassFieldTower.Cohomology.continuousH1CupModule
Source context 9 commands

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

open CategoryTheory TopRep ContRepresentation
open ClassFieldTower.ProP
open scoped Topology
namespace ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance continuousH1CupContinuousSMulULiftZMod :
    ContinuousSMul (ZMod p) (ULift.{u} (ZMod p)) :=
  ContinuousSMul.induced ULift.moduleEquiv.toLinearMap
instance continuousH1CupModule :
    Module (ZMod p) (ContinuousH1ZMod (p := p) (G := G))
ClassFieldTower.Cohomology.continuousH1CupHomogeneousTwoCochainLifted

The homogeneous degree-two cochain underlying the cup of two canonical continuous degree-one character cocycles.

Source context 10 commands

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

open CategoryTheory TopRep ContRepresentation
open ClassFieldTower.ProP
open scoped Topology
namespace ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance continuousH1CupContinuousSMulULiftZMod :
    ContinuousSMul (ZMod p) (ULift.{u} (ZMod p)) :=
  ContinuousSMul.induced ULift.moduleEquiv.toLinearMap
local instance continuousH1CupModule :
    Module (ZMod p) (ContinuousH1ZMod (p := p) (G := G)) :=
  continuousH1ZModModule
def continuousH1CupHomogeneousTwoCochainLifted
    (χ ψ : ContinuousH1ZMod (p := p) (G := G)) :
    (trivialZModPCochainsLifted p G).X 2
ClassFieldTower.Cohomology.continuousH1CupHomogeneousTwoCochainLifted_apply
Source context 10 commands

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

open CategoryTheory TopRep ContRepresentation
open ClassFieldTower.ProP
open scoped Topology
namespace ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance continuousH1CupContinuousSMulULiftZMod :
    ContinuousSMul (ZMod p) (ULift.{u} (ZMod p)) :=
  ContinuousSMul.induced ULift.moduleEquiv.toLinearMap
local instance continuousH1CupModule :
    Module (ZMod p) (ContinuousH1ZMod (p := p) (G := G)) :=
  continuousH1ZModModule
theorem continuousH1CupHomogeneousTwoCochainLifted_apply
    (χ ψ : ContinuousH1ZMod (p := p) (G := G)) (g h k : G) :
    (continuousH1CupHomogeneousTwoCochainLifted χ ψ).1 g h k =
      ULift.up
        (χ (Additive.ofMul (g⁻¹ * h)) *
          ψ (Additive.ofMul (h⁻¹ * k)))
ClassFieldTower.Cohomology.continuousH1CupHomogeneousTwoCochainLifted_mem_cycles

The canonical degree-two cup cochain satisfies the homogeneous cocycle equation.

Source context 10 commands

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

open CategoryTheory TopRep ContRepresentation
open ClassFieldTower.ProP
open scoped Topology
namespace ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance continuousH1CupContinuousSMulULiftZMod :
    ContinuousSMul (ZMod p) (ULift.{u} (ZMod p)) :=
  ContinuousSMul.induced ULift.moduleEquiv.toLinearMap
local instance continuousH1CupModule :
    Module (ZMod p) (ContinuousH1ZMod (p := p) (G := G)) :=
  continuousH1ZModModule
theorem continuousH1CupHomogeneousTwoCochainLifted_mem_cycles
    (χ ψ : ContinuousH1ZMod (p := p) (G := G)) :
    ((trivialZModPCochainsLifted p G).d 2 3).hom
        (continuousH1CupHomogeneousTwoCochainLifted χ ψ) = 0
ClassFieldTower.Cohomology.continuousH1CupHomogeneousTwoCochainLifted_add_left
Source context 10 commands

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

open CategoryTheory TopRep ContRepresentation
open ClassFieldTower.ProP
open scoped Topology
namespace ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance continuousH1CupContinuousSMulULiftZMod :
    ContinuousSMul (ZMod p) (ULift.{u} (ZMod p)) :=
  ContinuousSMul.induced ULift.moduleEquiv.toLinearMap
local instance continuousH1CupModule :
    Module (ZMod p) (ContinuousH1ZMod (p := p) (G := G)) :=
  continuousH1ZModModule
theorem continuousH1CupHomogeneousTwoCochainLifted_add_left
    (χ χ' ψ : ContinuousH1ZMod (p := p) (G := G)) :
    continuousH1CupHomogeneousTwoCochainLifted (χ + χ') ψ =
      continuousH1CupHomogeneousTwoCochainLifted χ ψ +
        continuousH1CupHomogeneousTwoCochainLifted χ' ψ
ClassFieldTower.Cohomology.continuousH1CupHomogeneousTwoCochainLifted_add_right
Source context 10 commands

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

open CategoryTheory TopRep ContRepresentation
open ClassFieldTower.ProP
open scoped Topology
namespace ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance continuousH1CupContinuousSMulULiftZMod :
    ContinuousSMul (ZMod p) (ULift.{u} (ZMod p)) :=
  ContinuousSMul.induced ULift.moduleEquiv.toLinearMap
local instance continuousH1CupModule :
    Module (ZMod p) (ContinuousH1ZMod (p := p) (G := G)) :=
  continuousH1ZModModule
theorem continuousH1CupHomogeneousTwoCochainLifted_add_right
    (χ ψ ψ' : ContinuousH1ZMod (p := p) (G := G)) :
    continuousH1CupHomogeneousTwoCochainLifted χ (ψ + ψ') =
      continuousH1CupHomogeneousTwoCochainLifted χ ψ +
        continuousH1CupHomogeneousTwoCochainLifted χ ψ'
ClassFieldTower.Cohomology.continuousH1CupHomogeneousTwoCochainLifted_smul_left
Source context 10 commands

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

open CategoryTheory TopRep ContRepresentation
open ClassFieldTower.ProP
open scoped Topology
namespace ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance continuousH1CupContinuousSMulULiftZMod :
    ContinuousSMul (ZMod p) (ULift.{u} (ZMod p)) :=
  ContinuousSMul.induced ULift.moduleEquiv.toLinearMap
local instance continuousH1CupModule :
    Module (ZMod p) (ContinuousH1ZMod (p := p) (G := G)) :=
  continuousH1ZModModule
theorem continuousH1CupHomogeneousTwoCochainLifted_smul_left
    (a : ZMod p) (χ ψ : ContinuousH1ZMod (p := p) (G := G)) :
    continuousH1CupHomogeneousTwoCochainLifted (a • χ) ψ =
      a • continuousH1CupHomogeneousTwoCochainLifted χ ψ
ClassFieldTower.Cohomology.continuousH1CupHomogeneousTwoCochainLifted_smul_right
Source context 10 commands

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

open CategoryTheory TopRep ContRepresentation
open ClassFieldTower.ProP
open scoped Topology
namespace ClassFieldTower.Cohomology
noncomputable section
universe u
variable {p : ℕ}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance continuousH1CupContinuousSMulULiftZMod :
    ContinuousSMul (ZMod p) (ULift.{u} (ZMod p)) :=
  ContinuousSMul.induced ULift.moduleEquiv.toLinearMap
local instance continuousH1CupModule :
    Module (ZMod p) (ContinuousH1ZMod (p := p) (G := G)) :=
  continuousH1ZModModule
theorem continuousH1CupHomogeneousTwoCochainLifted_smul_right
    (a : ZMod p) (χ ψ : ContinuousH1ZMod (p := p) (G := G)) :
    continuousH1CupHomogeneousTwoCochainLifted χ (a • ψ) =
      a • continuousH1CupHomogeneousTwoCochainLifted χ ψ