Module

ModPTailExactness.lean

Nyll.ProCGroups.ProP.Fox.ModPTailExactness
5 declarations indexed from sourceView source ↗

Tail exactness of the mod-p Fox boundary

The completed mod-p Fox boundary has closed range. Density of the algebraic group algebra, together with the presentation fundamental formula, identifies that range with the canonical augmentation ideal.

Declarations

ClassFieldTower.ProP.isClosed_range_presentationModPFoxBoundary

The range of the completed mod-p Fox boundary is closed.

Source context 12 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open CompletedGroupAlgebra
open FoxDifferential
open ProCGroups
open ProCGroups.ProC
noncomputable section
universe u
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]
theorem isClosed_range_presentationModPFoxBoundary
    (P : FiniteProPPresentation p d r sourceData G) :
    IsClosed (Set.range (presentationModPFoxBoundary P))
ClassFieldTower.ProP.presentationModPFoxBoundary_mem_augmentationIdeal

The completed Fox boundary lands in the canonical augmentation ideal.

Source context 12 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open CompletedGroupAlgebra
open FoxDifferential
open ProCGroups
open ProCGroups.ProC
noncomputable section
universe u
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]
theorem presentationModPFoxBoundary_mem_augmentationIdeal
    (P : FiniteProPPresentation p d r sourceData G)
    (v : PresentationModPFoxCoordinates (p := p) (d := d) (G := G)) :
    presentationModPFoxBoundary P v ∈ modPAugmentationIdeal p G
ClassFieldTower.ProP.groupLikeDifference_mem_presentationModPFoxBoundary_range

Every standard completed augmentation generator is in the boundary range.

Source context 12 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open CompletedGroupAlgebra
open FoxDifferential
open ProCGroups
open ProCGroups.ProC
noncomputable section
universe u
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]
theorem groupLikeDifference_mem_presentationModPFoxBoundary_range
    (P : FiniteProPPresentation p d r sourceData G) (g : G) :
    groupLikeDifference p G g ∈ LinearMap.range (presentationModPFoxBoundary P)
ClassFieldTower.ProP.toCompletedGroupAlgebraInClass_mem_presentationModPFoxBoundary_range

The dense algebraic augmentation ideal maps into the completed boundary range.

Source context 12 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open CompletedGroupAlgebra
open FoxDifferential
open ProCGroups
open ProCGroups.ProC
noncomputable section
universe u
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]
theorem toCompletedGroupAlgebraInClass_mem_presentationModPFoxBoundary_range
    (P : FiniteProPPresentation p d r sourceData G)
    (a : MonoidAlgebra (ZMod p) G)
    (ha : a ∈ groupAlgebraAugmentationIdeal (ZMod p) G) :
    toCompletedGroupAlgebraInClass
        (FiniteGroupClass.pGroup p) (ZMod p) G a ∈
      LinearMap.range (presentationModPFoxBoundary P)
ClassFieldTower.ProP.presentationModPFoxBoundary_range_eq_augmentationIdeal

The completed mod-p Fox boundary has range equal to the canonical augmentation ideal.

Source context 12 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open CompletedGroupAlgebra
open FoxDifferential
open ProCGroups
open ProCGroups.ProC
noncomputable section
universe u
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]
theorem presentationModPFoxBoundary_range_eq_augmentationIdeal
    (P : FiniteProPPresentation p d r sourceData G) :
    LinearMap.range (presentationModPFoxBoundary P) =
      (modPAugmentationIdeal p G :
        Submodule (ModPCompletedGroupAlgebra p G)
          (ModPCompletedGroupAlgebra p G))