Module

GeneratorRank.lean

Nyll.ProCGroups.ProP.Presentation.GeneratorRank
5 declarations indexed from sourceView source ↗

Generator rank of a minimal pro-p presentation

The displayed free basis gives the upper rank bound. Minimality supplies a surjection from the target to the source Frattini quotient, and the Burnside basis theorem lifts a small generating set back to the free source, giving the reverse bound.

Declarations

Source context 13 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open ProCGroups
open ProCGroups.FiniteGeneration
open ProCGroups.Generation
open ProCGroups.Presentations
noncomputable section
universe u
namespace FiniteProPPresentation
variable {p d r : ℕ} [Fact p.Prime]
variable {sourceData :
  FreeProC.EpimorphicallyFreeProCGroupOnConvergingSetData.{u, u}
    (FiniteGroupClass.pGroup p)}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
instance : (closedPowerCommutator p sourceData.carrier).Normal
ClassFieldTower.ProP.FiniteProPPresentation.target_topologicallyGeneratedByAtMost

The displayed free basis gives an at-most-d generating family of the target.

Source context 14 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open ProCGroups
open ProCGroups.FiniteGeneration
open ProCGroups.Generation
open ProCGroups.Presentations
noncomputable section
universe u
namespace FiniteProPPresentation
variable {p d r : ℕ} [Fact p.Prime]
variable {sourceData :
  FreeProC.EpimorphicallyFreeProCGroupOnConvergingSetData.{u, u}
    (FiniteGroupClass.pGroup p)}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
local instance : (closedPowerCommutator p sourceData.carrier).Normal :=
  closedPowerCommutator_normal p sourceData.carrier
theorem target_topologicallyGeneratedByAtMost
    (P : FiniteProPPresentation p d r sourceData G) :
    TopologicallyGeneratedByAtMost (G := G) d
ClassFieldTower.ProP.FiniteProPPresentation.source_topologicalRank_eq_nat

The free source has the displayed generator rank.

Source context 14 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open ProCGroups
open ProCGroups.FiniteGeneration
open ProCGroups.Generation
open ProCGroups.Presentations
noncomputable section
universe u
namespace FiniteProPPresentation
variable {p d r : ℕ} [Fact p.Prime]
variable {sourceData :
  FreeProC.EpimorphicallyFreeProCGroupOnConvergingSetData.{u, u}
    (FiniteGroupClass.pGroup p)}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
local instance : (closedPowerCommutator p sourceData.carrier).Normal :=
  closedPowerCommutator_normal p sourceData.carrier
theorem source_topologicalRank_eq_nat
    (P : FiniteProPPresentation p d r sourceData G) :
    topologicalRank sourceData.carrier = d
ClassFieldTower.ProP.FiniteProPPresentation.target_topologicalRank_eq_nat

Minimality forces the target generator rank to equal the displayed free rank.

Source context 14 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open ProCGroups
open ProCGroups.FiniteGeneration
open ProCGroups.Generation
open ProCGroups.Presentations
noncomputable section
universe u
namespace FiniteProPPresentation
variable {p d r : ℕ} [Fact p.Prime]
variable {sourceData :
  FreeProC.EpimorphicallyFreeProCGroupOnConvergingSetData.{u, u}
    (FiniteGroupClass.pGroup p)}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
local instance : (closedPowerCommutator p sourceData.carrier).Normal :=
  closedPowerCommutator_normal p sourceData.carrier
theorem target_topologicalRank_eq_nat
    (P : FiniteProPPresentation p d r sourceData G) (hP : P.IsMinimal) :
    topologicalRank G = d
ClassFieldTower.ProP.FiniteProPPresentation.target_topologicalGeneratorRank_eq

Natural-valued generator-rank form of target_topologicalRank_eq_nat.

Source context 14 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open ProCGroups
open ProCGroups.FiniteGeneration
open ProCGroups.Generation
open ProCGroups.Presentations
noncomputable section
universe u
namespace FiniteProPPresentation
variable {p d r : ℕ} [Fact p.Prime]
variable {sourceData :
  FreeProC.EpimorphicallyFreeProCGroupOnConvergingSetData.{u, u}
    (FiniteGroupClass.pGroup p)}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
local instance : (closedPowerCommutator p sourceData.carrier).Normal :=
  closedPowerCommutator_normal p sourceData.carrier
theorem target_topologicalGeneratorRank_eq
    (P : FiniteProPPresentation p d r sourceData G) (hP : P.IsMinimal) :
    topologicalGeneratorRank G = d