Module

Comparison.lean

Nyll.ProCGroups.CompletedGroupAlgebra.InClassFunctoriality.Comparison
8 declarations indexed from sourceView source ↗

Comparison maps for in-class completions

This file computes the canonical maps between all-finite and in-class completed group algebras on group-like elements and their differences from one. It also records the corresponding formulas for functorial maps and restricted scalar actions.

Declarations

CompletedGroupAlgebra.completedGroupAlgebraToInClass_of

The all-finite completed group algebra comparison sends group-like elements to the \(C\)-indexed group-like elements.

Source context 10 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
universe u v w
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
theorem completedGroupAlgebraToInClass_of
    (C : ProCGroups.FiniteGroupClass.{v})
    (g : G) :
    completedGroupAlgebraToInClassRingHom (R := R) (G := G) C
        (completedGroupAlgebraOf R G g) =
      completedGroupAlgebraOfInClass C R G g
CompletedGroupAlgebra.completedGroupAlgebraToInClass_of_sub_one

The comparison map to a class-indexed completion sends all-finite augmentation generators to class-indexed generators.

Source context 10 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
universe u v w
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
theorem completedGroupAlgebraToInClass_of_sub_one
    (C : ProCGroups.FiniteGroupClass.{v})
    (g : G) :
    completedGroupAlgebraToInClassRingHom (R := R) (G := G) C
        (completedGroupAlgebraOf R G g - 1) =
      completedGroupAlgebraOfInClass C R G g - 1
CompletedGroupAlgebra.completedGroupAlgebraToInClass_restrictScalars_sub_one_smul

After restricting scalars along \(\widehat{R[G]} \to \widehat{R[G]}_C\), the all-finite augmentation generator acts as the matching \(C\)-indexed generator.

Source context 10 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
universe u v w
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
theorem completedGroupAlgebraToInClass_restrictScalars_sub_one_smul
    (C : ProCGroups.FiniteGroupClass.{v})
    (A : Type w) [AddCommGroup A] [Module (CompletedGroupAlgebraInClass C R G) A]
    (g : G) (a : A) :
    letI : Module (CompletedGroupAlgebraCarrier R G) A :=
      Module.compHom A (completedGroupAlgebraToInClassRingHom (R := R) (G := G) C )
    (completedGroupAlgebraOf R G g - 1) • a =
      (completedGroupAlgebraOfInClass C R G g - 1) • a := by
  exact congrArg (fun z : CompletedGroupAlgebraInClass C R G => z • a)
    (completedGroupAlgebraToInClass_of_sub_one (R := R) (G := G) C g)
CompletedGroupAlgebra.completedGroupAlgebraFromInClass_of

The comparison map from a class-indexed completion sends class-indexed group-like elements to all-finite group-like elements.

Source context 10 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
universe u v w
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
theorem completedGroupAlgebraFromInClass_of
    (C : ProCGroups.FiniteGroupClass.{v})
    (hForm : ProCGroups.FiniteGroupClass.Formation C) (hG : HasOpenNormalBasisInClass C G) (g : G) :
    completedGroupAlgebraFromInClass (R := R) (G := G) C hForm hG
        (completedGroupAlgebraOfInClass C R G g) =
      completedGroupAlgebraOf R G g
CompletedGroupAlgebra.completedGroupAlgebraFromInClass_of_sub_one

The comparison map from a class-indexed completion sends class-indexed augmentation generators to all-finite generators.

Source context 10 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
universe u v w
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
theorem completedGroupAlgebraFromInClass_of_sub_one
    (C : ProCGroups.FiniteGroupClass.{v})
    (hForm : ProCGroups.FiniteGroupClass.Formation C) (hG : HasOpenNormalBasisInClass C G) (g : G) :
    completedGroupAlgebraFromInClass (R := R) (G := G) C hForm hG
        (completedGroupAlgebraOfInClass C R G g - 1) =
      completedGroupAlgebraOf R G g - 1
CompletedGroupAlgebra.completedGroupAlgebraFromInClass_restrictScalars_sub_one_smul

After restricting scalars along \(\widehat{R[G]}_C \to \widehat{R[G]}\), the \(C\)-indexed augmentation generator acts as the matching all-finite generator.

Source context 10 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
universe u v w
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
theorem completedGroupAlgebraFromInClass_restrictScalars_sub_one_smul
    (C : ProCGroups.FiniteGroupClass.{v})
    (hForm : ProCGroups.FiniteGroupClass.Formation C) (hG : HasOpenNormalBasisInClass C G)
    (A : Type w) [AddCommGroup A] [Module (CompletedGroupAlgebraCarrier R G) A]
    (g : G) (a : A) :
    letI : Module (CompletedGroupAlgebraInClass C R G) A :=
      Module.compHom A (completedGroupAlgebraFromInClassRingHom (R := R) (G := G) C hForm hG)
    (completedGroupAlgebraOfInClass C R G g - 1) • a =
      (completedGroupAlgebraOf R G g - 1) • a := by
  exact congrArg (fun z : CompletedGroupAlgebraCarrier R G => z • a)
    (completedGroupAlgebraFromInClass_of_sub_one (R := R) (G := G) C hForm hG g)
CompletedGroupAlgebra.completedGroupAlgebraMapInClass_of

The class-indexed completed group-algebra map sends the completed group-like element of \(g\) to the completed group-like element of its image.

Source context 10 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
universe u v w
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
theorem completedGroupAlgebraMapInClass_of
    (C : ProCGroups.FiniteGroupClass.{v})
    (hHer : ProCGroups.FiniteGroupClass.Hereditary C)
    (φ : G →* H) (hφ : Continuous φ) (g : G) :
    completedGroupAlgebraMapInClass (G := G) (H := H) C hHer R φ hφ
        (completedGroupAlgebraOfInClass C R G g) =
      completedGroupAlgebraOfInClass C R H (φ g)
CompletedGroupAlgebra.completedGroupAlgebraMapInClass_of_sub_one

The class-indexed functorial map sends group-like augmentation generators to their images.

Source context 10 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
universe u v w
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
theorem completedGroupAlgebraMapInClass_of_sub_one
    (C : ProCGroups.FiniteGroupClass.{v})
    (hHer : ProCGroups.FiniteGroupClass.Hereditary C)
    (φ : G →* H) (hφ : Continuous φ) (g : G) :
    completedGroupAlgebraMapInClass (G := G) (H := H) C hHer R φ hφ
        (completedGroupAlgebraOfInClass C R G g - 1) =
      completedGroupAlgebraOfInClass C R H (φ g) - 1