Module

CompletedGroupAlgebra.lean

Nyll.ProCGroups.FoxDifferential.Completed.CoefficientRings.CompletedGroupAlgebra
22 declarations indexed from sourceView source ↗

Fox differential: completed — coefficient rings — completed group algebra

The principal declarations in this module are:

  • CompletedGroupAlgebraIndexInClass

The index set for a completed group algebra over finite quotients belonging to a class C.

  • CompletedGroupAlgebraQuotientInClass

The finite quotient of G attached to one class-restricted completed-group-algebra stage.

  • completedGroupAlgebraTransitionInClass_id

Identity case for completedGroupAlgebraTransitionInClass_id.

  • completedGroupAlgebraTransitionInClass_comp

Composition lemma completedGroupAlgebraTransitionInClass_comp.

Declarations

FoxDifferential.CompletedGroupAlgebraIndexInClass

The index set for a completed group algebra over finite quotients belonging to a class C.

Source context 9 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
abbrev CompletedGroupAlgebraIndexInClass (C : ProCGroups.FiniteGroupClass.{u})
FoxDifferential.CompletedGroupAlgebraQuotientInClass

The finite quotient of G attached to one class-restricted completed-group-algebra stage.

Source context 9 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
abbrev CompletedGroupAlgebraQuotientInClass
    (C : ProCGroups.FiniteGroupClass.{u}) (U : CompletedGroupAlgebraIndexInClass G C) : Type _
FoxDifferential.CompletedGroupAlgebraStageInClass

The discrete group ring over one class-restricted finite quotient of G.

Source context 9 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
abbrev CompletedGroupAlgebraStageInClass
    (C : ProCGroups.FiniteGroupClass.{u}) (U : CompletedGroupAlgebraIndexInClass G C) : Type _
FoxDifferential.completedGroupAlgebraTransitionInClass

The transition map between two class-restricted completed-group-algebra stages.

Source context 9 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
def completedGroupAlgebraTransitionInClass
    (C : ProCGroups.FiniteGroupClass.{u})
    {U V : CompletedGroupAlgebraIndexInClass G C} (hUV : U ≤ V) :
    CompletedGroupAlgebraStageInClass G C V →+*
      CompletedGroupAlgebraStageInClass G C U
FoxDifferential.completedGroupAlgebraTransitionInClass_id

Identity case for completedGroupAlgebraTransitionInClass_id.

Source context 9 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
theorem completedGroupAlgebraTransitionInClass_id
    (C : ProCGroups.FiniteGroupClass.{u}) (U : CompletedGroupAlgebraIndexInClass G C) :
    completedGroupAlgebraTransitionInClass G C (le_rfl : U ≤ U) = RingHom.id _
FoxDifferential.completedGroupAlgebraTransitionInClass_comp

Composition lemma completedGroupAlgebraTransitionInClass_comp.

Source context 9 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
theorem completedGroupAlgebraTransitionInClass_comp
    (C : ProCGroups.FiniteGroupClass.{u})
    {U V W : CompletedGroupAlgebraIndexInClass G C} (hUV : U ≤ V) (hVW : V ≤ W) :
    (completedGroupAlgebraTransitionInClass G C hUV).comp
        (completedGroupAlgebraTransitionInClass G C hVW) =
      completedGroupAlgebraTransitionInClass G C (hUV.trans hVW)
FoxDifferential.completedGroupAlgebraSystemInClass

The class-restricted inverse system of finite-stage integral group rings.

Source context 9 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
def completedGroupAlgebraSystemInClass
    (C : ProCGroups.FiniteGroupClass.{u}) :
    InverseSystem (I := CompletedGroupAlgebraIndexInClass G C) where
  X := CompletedGroupAlgebraStageInClass G C
  topologicalSpace := fun _ => ⊥
  map := fun {U V} hUV => completedGroupAlgebraTransitionInClass G C hUV
  continuous_map := by
    intro U V hUV
    let : TopologicalSpace (CompletedGroupAlgebraStageInClass G C U) := ⊥
    let : TopologicalSpace (CompletedGroupAlgebraStageInClass G C V) := ⊥
    let : DiscreteTopology (CompletedGroupAlgebraStageInClass G C V) := ⟨rfl⟩
    exact continuous_of_discreteTopology
  map_id := by
    intro U
    funext x
    exact congrFun
      (congrArg DFunLike.coe
        (completedGroupAlgebraTransitionInClass_id G C U)) x
  map_comp := by
    intro U V W hUV hVW
    funext x
    exact congrFun
      (congrArg DFunLike.coe
        (completedGroupAlgebraTransitionInClass_comp G C hUV hVW)) x
FoxDifferential.completedGroupAlgebraStageMapInClass

The quotient ring map from ℤ[G] to one class-restricted finite stage.

Source context 9 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
def completedGroupAlgebraStageMapInClass
    (C : ProCGroups.FiniteGroupClass.{u}) (U : CompletedGroupAlgebraIndexInClass G C) :
    MonoidAlgebra ℤ G →+* CompletedGroupAlgebraStageInClass G C U
FoxDifferential.completedGroupAlgebraStageMapInClass_of

Evaluation formula for completedGroupAlgebraStageMapInClass_of.

Source context 9 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
theorem completedGroupAlgebraStageMapInClass_of
    (C : ProCGroups.FiniteGroupClass.{u}) (U : CompletedGroupAlgebraIndexInClass G C) (g : G) :
    completedGroupAlgebraStageMapInClass G C U (MonoidAlgebra.of ℤ _ g) =
      MonoidAlgebra.single (openNormalSubgroupInClassProj (C := C) (G := G) U g) 1
FoxDifferential.completedGroupAlgebraStageMapInClass_compatible

Compatibility lemma completedGroupAlgebraStageMapInClass_compatible.

Source context 9 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
theorem completedGroupAlgebraStageMapInClass_compatible
    (C : ProCGroups.FiniteGroupClass.{u})
    {U V : CompletedGroupAlgebraIndexInClass G C} (hUV : U ≤ V) :
    (completedGroupAlgebraTransitionInClass G C hUV).comp
        (completedGroupAlgebraStageMapInClass G C V) =
      completedGroupAlgebraStageMapInClass G C U
FoxDifferential.CompletedGroupAlgebraCompatibleInClass

Compatibility for a class-restricted completed group algebra family.

Source context 9 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
def CompletedGroupAlgebraCompatibleInClass
    (C : ProCGroups.FiniteGroupClass.{u})
    (x : ∀ U : CompletedGroupAlgebraIndexInClass G C,
      CompletedGroupAlgebraStageInClass G C U) : Prop
FoxDifferential.CompletedGroupAlgebraInClass

The class-restricted completed group algebra as an inverse-limit subtype.

Source context 9 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
abbrev CompletedGroupAlgebraInClass (C : ProCGroups.FiniteGroupClass.{u}) : Type _
FoxDifferential.completedGroupAlgebraProjectionInClass

Projection from the class-restricted completed group algebra to one finite stage.

Source context 9 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
def completedGroupAlgebraProjectionInClass
    (C : ProCGroups.FiniteGroupClass.{u}) (U : CompletedGroupAlgebraIndexInClass G C) :
    CompletedGroupAlgebraInClass G C → CompletedGroupAlgebraStageInClass G C U
FoxDifferential.completedGroupAlgebraComapIndexInClass

Pull back a class-restricted finite quotient along a continuous homomorphism.

The hereditary hypothesis is the precise extra closure property needed: the pulled-back quotient embeds into the target quotient, so membership in C follows from closure under subgroups.

Source context 13 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
section ComapInClass
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
def completedGroupAlgebraComapIndexInClass
    (C : ProCGroups.FiniteGroupClass.{u}) (hC : ProCGroups.FiniteGroupClass.Hereditary C)
    (ψ : ContinuousMonoidHom G H) (U : CompletedGroupAlgebraIndexInClass H C) :
    CompletedGroupAlgebraIndexInClass G C
FoxDifferential.completedGroupAlgebraComapQuotientMapInClass

The finite quotient map induced by a continuous homomorphism after pulling back the stage.

Source context 13 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
section ComapInClass
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
def completedGroupAlgebraComapQuotientMapInClass
    (C : ProCGroups.FiniteGroupClass.{u}) (hC : ProCGroups.FiniteGroupClass.Hereditary C)
    (ψ : ContinuousMonoidHom G H) (U : CompletedGroupAlgebraIndexInClass H C) :
    CompletedGroupAlgebraQuotientInClass G C
        (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hC ψ U) →*
      CompletedGroupAlgebraQuotientInClass H C U
FoxDifferential.completedGroupAlgebraComapQuotientMapInClass_mk

Evaluation formula for completedGroupAlgebraComapQuotientMapInClass_mk.

Source context 13 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
section ComapInClass
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
theorem completedGroupAlgebraComapQuotientMapInClass_mk
    (C : ProCGroups.FiniteGroupClass.{u}) (hC : ProCGroups.FiniteGroupClass.Hereditary C)
    (ψ : ContinuousMonoidHom G H) (U : CompletedGroupAlgebraIndexInClass H C) (g : G) :
    completedGroupAlgebraComapQuotientMapInClass
        (G := G) (H := H) C hC ψ U
        (QuotientGroup.mk'
          ((((OrderDual.ofDual
            (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hC ψ U)).1 :
              OpenNormalSubgroup G) : Subgroup G)) g) =
      QuotientGroup.mk' ((((OrderDual.ofDual U).1 : OpenNormalSubgroup H) : Subgroup H))
        (ψ g)
FoxDifferential.completedGroupAlgebraComapQuotientMapInClass_surjective_of_surjective

Surjectivity lemma completedGroupAlgebraComapQuotientMapInClass_surjective_of_surjective.

Source context 13 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
section ComapInClass
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
theorem completedGroupAlgebraComapQuotientMapInClass_surjective_of_surjective
    (C : ProCGroups.FiniteGroupClass.{u}) (hC : ProCGroups.FiniteGroupClass.Hereditary C)
    (ψ : ContinuousMonoidHom G H) (hψ : Function.Surjective ψ)
    (U : CompletedGroupAlgebraIndexInClass H C) :
    Function.Surjective
      (completedGroupAlgebraComapQuotientMapInClass (G := G) (H := H) C hC ψ U)
FoxDifferential.completedGroupAlgebraComapIndexInClass_mono

有限群クラスを固定した 標準写像が対応する有限段階・係数段階・augmentation 構造と両立することを述べる。

Source context 14 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
section ComapInClass
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
omit [IsTopologicalGroup G] in
theorem completedGroupAlgebraComapIndexInClass_mono
    (C : ProCGroups.FiniteGroupClass.{u}) (hC : ProCGroups.FiniteGroupClass.Hereditary C)
    (ψ : ContinuousMonoidHom G H) {U V : CompletedGroupAlgebraIndexInClass H C}
    (hUV : U ≤ V) :
    completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hC ψ U ≤
      completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hC ψ V
FoxDifferential.completedGroupAlgebraComapQuotientMapInClass_compatible

Compatibility lemma completedGroupAlgebraComapQuotientMapInClass_compatible.

Source context 13 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
section ComapInClass
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
theorem completedGroupAlgebraComapQuotientMapInClass_compatible
    (C : ProCGroups.FiniteGroupClass.{u}) (hC : ProCGroups.FiniteGroupClass.Hereditary C)
    (ψ : ContinuousMonoidHom G H) {U V : CompletedGroupAlgebraIndexInClass H C}
    (hUV : U ≤ V) :
    (OpenNormalSubgroupInClass.map
        (C := C) (G := H)
        (U := OrderDual.ofDual U) (V := OrderDual.ofDual V) hUV).comp
        (completedGroupAlgebraComapQuotientMapInClass (G := G) (H := H) C hC ψ V) =
      (completedGroupAlgebraComapQuotientMapInClass (G := G) (H := H) C hC ψ U).comp
        (OpenNormalSubgroupInClass.map
          (C := C) (G := G)
          (U := OrderDual.ofDual
            (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hC ψ U))
          (V := OrderDual.ofDual
            (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hC ψ V))
          (completedGroupAlgebraComapIndexInClass_mono (G := G) (H := H) C hC ψ hUV))
FoxDifferential.completedGroupAlgebraComapIndexInClass_id

Pulling a finite quotient back along the identity continuous homomorphism gives the same class-restricted index. This is intentionally an equality theorem, since dependent inverse-limit indices are often not definitionally equal after target naturality rewrites.

Source context 13 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
section ComapInClass
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
theorem completedGroupAlgebraComapIndexInClass_id
    (C : ProCGroups.FiniteGroupClass.{u}) (hC : ProCGroups.FiniteGroupClass.Hereditary C)
    (U : CompletedGroupAlgebraIndexInClass G C) :
    completedGroupAlgebraComapIndexInClass (G := G) (H := G) C hC
        (ContinuousMonoidHom.id G) U = U
FoxDifferential.completedGroupAlgebraComapIndexInClass_comp

Pullback of class-restricted finite quotients is functorial for continuous target maps.

This is the index-level rewrite needed when the two inverse-limit stage indices produced by a composite target map are propositionally, but not definitionally, the same.

Source context 14 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
section ComapInClass
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
omit [IsTopologicalGroup G] in
theorem completedGroupAlgebraComapIndexInClass_comp
    (C : ProCGroups.FiniteGroupClass.{u}) (hC : ProCGroups.FiniteGroupClass.Hereditary C)
    {K : Type u} [Group K] [TopologicalSpace K] [IsTopologicalGroup K]
    (φ : G →ₜ* H) (ψ : H →ₜ* K) (U : CompletedGroupAlgebraIndexInClass K C) :
    completedGroupAlgebraComapIndexInClass (G := G) (H := K) C hC (ψ.comp φ) U =
      completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hC φ
        (completedGroupAlgebraComapIndexInClass (G := H) (H := K) C hC ψ U)
FoxDifferential.completedGroupAlgebraComapIndexInClass_top

Pulling back the canonical trivial quotient gives the canonical trivial quotient.

Source context 14 commands

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

namespace FoxDifferential
open Set
open ProCGroups
open ProCGroups.InverseSystems
open ProCGroups.ProC
open scoped Topology
noncomputable section
universe u v w
variable (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
section ComapInClass
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
omit [IsTopologicalGroup G] in
theorem completedGroupAlgebraComapIndexInClass_top
    (C : ProCGroups.FiniteGroupClass.{u}) (hC : ProCGroups.FiniteGroupClass.Hereditary C)
    [ProCGroups.FiniteGroupClass.ContainsTrivialQuotients C]
    (ψ : G →ₜ* H) :
    completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hC ψ
        (OrderDual.toDual (OpenNormalSubgroupInClass.top (C := C) (G := H))) =
      OrderDual.toDual (OpenNormalSubgroupInClass.top (C := C) (G := G))