Module

ContinuousTransgressionPrimitive.lean

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

Primitives for continuous inflation--transgression exactness

This file extracts the normalized degree-one primitive of an inflated degree-two cocycle and uses its restriction to the open normal subgroup to reconstruct the invariant continuous character occurring in transgression.

Imports9
  • Nyll.GaloisCohomology.ProP.InflationTransgressionRange
  • Mathlib.RepresentationTheory.Homological.ContCohomology.Basic
  • Mathlib.RepresentationTheory.Continuous.Basic
  • Mathlib.RepresentationTheory.Continuous.TopRep
  • Mathlib.Topology.ContinuousMap.Algebra
  • Mathlib.Topology.ContinuousMap.Basic
  • Mathlib.Topology.ContinuousMap.Defs
  • Mathlib.Algebra.Group.Defs
  • Mathlib.Algebra.Group.Basic
Imported by2

Declarations

ClassFieldTower.Cohomology.normalizedInflationPrimitiveValue

Normalize a homogeneous degree-one cochain at the identity.

Source context 11 commands

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

open CategoryTheory TopRep ContRepresentation
open scoped Topology
namespace ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
open ClassFieldTower.ProP
open ClassFieldTower.ProP.FreeProPH2Cocycle
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
def normalizedInflationPrimitiveValue
    (c : (trivialZModPCochainsLifted p G).X 1) :
    C(G, ULift.{u} (ZMod p)) where
  toFun g := c.1 1 g - c.1 1 1
  continuous_toFun := (c.1 1).continuous.sub continuous_const
ClassFieldTower.Cohomology.normalizedInflationPrimitiveValue_one
Source context 12 commands

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

open CategoryTheory TopRep ContRepresentation
open scoped Topology
namespace ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
open ClassFieldTower.ProP
open ClassFieldTower.ProP.FreeProPH2Cocycle
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
omit [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G] in
theorem normalizedInflationPrimitiveValue_one
    (c : (trivialZModPCochainsLifted p G).X 1) :
    normalizedInflationPrimitiveValue c 1 = 0
ClassFieldTower.Cohomology.normalizedInflationPrimitive_boundary
Source context 12 commands

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

open CategoryTheory TopRep ContRepresentation
open scoped Topology
namespace ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
open ClassFieldTower.ProP
open ClassFieldTower.ProP.FreeProPH2Cocycle
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
omit [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G] in
theorem normalizedInflationPrimitive_boundary
    (U : OpenNormalSubgroupInClass (FiniteGroupClass.pGroup p) G)
    (z : trivialZModPCocyclesLifted p (G ⧸ (U.1 : Subgroup G)) 2)
    (c : (trivialZModPCochainsLifted p G).X 1)
    (hc : ((trivialZModPCochainsLifted p G).d 1 2).hom c =
      (((trivialZModPCochainsMapLifted p
        (OpenNormalSubgroupInClass.quotientProj U)).f 2).hom
          (((trivialZModPCochainsLifted p
            (G ⧸ (U.1 : Subgroup G))).iCycles 2).hom z)))
    (g h : G) :
    normalizedInflationPrimitiveValue c h -
        normalizedInflationPrimitiveValue c (g * h) +
          normalizedInflationPrimitiveValue c g =
      normalizedCocycle z
        (OpenNormalSubgroupInClass.quotientProj U g)
        (OpenNormalSubgroupInClass.quotientProj U h)
ClassFieldTower.Cohomology.invariantContinuousH1OfInflationPrimitive

Restrict the negative normalized primitive to the open normal subgroup. The boundary identity makes it a continuous character, and makes that character invariant under ambient conjugation.

Source context 11 commands

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

open CategoryTheory TopRep ContRepresentation
open scoped Topology
namespace ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
open ClassFieldTower.ProP
open ClassFieldTower.ProP.FreeProPH2Cocycle
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
def invariantContinuousH1OfInflationPrimitive
    (U : OpenNormalSubgroupInClass (FiniteGroupClass.pGroup p) G)
    (z : trivialZModPCocyclesLifted p (G ⧸ (U.1 : Subgroup G)) 2)
    (c : (trivialZModPCochainsLifted p G).X 1)
    (hc : ((trivialZModPCochainsLifted p G).d 1 2).hom c =
      (((trivialZModPCochainsMapLifted p
        (OpenNormalSubgroupInClass.quotientProj U)).f 2).hom
          (((trivialZModPCochainsLifted p
            (G ⧸ (U.1 : Subgroup G))).iCycles 2).hom z))) :
    InvariantContinuousH1 U
ClassFieldTower.Cohomology.inflationPrimitiveQuotientCorrection

The quotient correction obtained by evaluating the normalized primitive on chosen quotient representatives.

Source context 11 commands

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

open CategoryTheory TopRep ContRepresentation
open scoped Topology
namespace ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
open ClassFieldTower.ProP
open ClassFieldTower.ProP.FreeProPH2Cocycle
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
def inflationPrimitiveQuotientCorrection
    (U : OpenNormalSubgroupInClass (FiniteGroupClass.pGroup p) G)
    (c : (trivialZModPCochainsLifted p G).X 1) :
    C(G ⧸ (U.1 : Subgroup G), ULift.{u} (ZMod p)) where
  toFun q := normalizedInflationPrimitiveValue c (Quotient.out q) -
    normalizedInflationPrimitiveValue c
      (Quotient.out (1 : G ⧸ (U.1 : Subgroup G)))
  continuous_toFun := continuous_of_discreteTopology
ClassFieldTower.Cohomology.reconstructed_transgressionFactor
Source context 12 commands

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

open CategoryTheory TopRep ContRepresentation
open scoped Topology
namespace ClassFieldTower.Cohomology
open ProCGroups ProCGroups.ProC
open ClassFieldTower.ProP
open ClassFieldTower.ProP.FreeProPH2Cocycle
noncomputable section
universe u
variable {p : ℕ} [Fact p.Prime]
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
omit [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G] in
theorem reconstructed_transgressionFactor
    (U : OpenNormalSubgroupInClass (FiniteGroupClass.pGroup p) G)
    (z : trivialZModPCocyclesLifted p (G ⧸ (U.1 : Subgroup G)) 2)
    (c : (trivialZModPCochainsLifted p G).X 1)
    (hc : ((trivialZModPCochainsLifted p G).d 1 2).hom c =
      (((trivialZModPCochainsMapLifted p
        (OpenNormalSubgroupInClass.quotientProj U)).f 2).hom
          (((trivialZModPCochainsLifted p
            (G ⧸ (U.1 : Subgroup G))).iCycles 2).hom z)))
    (q r : G ⧸ (U.1 : Subgroup G)) :
    ULift.up (transgressionFactor (U.1 : Subgroup G)
        (characterOfH1
          (invariantContinuousH1OfInflationPrimitive U z c hc).1).toMonoidHom q r) =
      normalizedCocycle z q r -
        normalizedInflationPrimitiveValue c (Quotient.out q) -
        normalizedInflationPrimitiveValue c (Quotient.out r) +
        normalizedInflationPrimitiveValue c (Quotient.out (q * r))