Module

StageMaps.lean

Nyll.ProCGroups.CompletedGroupAlgebra.InClassFunctoriality.StageMaps
9 declarations indexed from sourceView source ↗

Functorial maps at in-class finite stages

This file constructs the finite-stage group-algebra map induced by a continuous group homomorphism. It proves formulas on basis elements and scalars and compatibility with coefficient change, transitions, and the completed map.

Declarations

CompletedGroupAlgebra.completedGroupAlgebraFunctorialStageMapInClass

The \(C\)-indexed finite-stage map \(R[G/\varphi^{-1}(V)]\to R[H/V]\) is induced by a continuous homomorphism \(\varphi : G \to H\).

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]
def completedGroupAlgebraFunctorialStageMapInClass
    (C : ProCGroups.FiniteGroupClass.{v}) (hHer : ProCGroups.FiniteGroupClass.Hereditary C)
    (R : Type u) [CommRing R] (φ : G →* H) (hφ : Continuous φ)
    (V : CompletedGroupAlgebraIndexInClass H C) :
    CompletedGroupAlgebraStageInClass C R G
        (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hHer φ hφ V) →+*
      CompletedGroupAlgebraStageInClass C R H V
CompletedGroupAlgebra.completedGroupAlgebraFunctorialStageMapInClass_surjective_of_surjective

A surjective group homomorphism induces a surjective finite-stage group-algebra map.

Source context 11 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]
omit [TopologicalSpace R] [IsTopologicalRing R] in
theorem completedGroupAlgebraFunctorialStageMapInClass_surjective_of_surjective
    (C : ProCGroups.FiniteGroupClass.{v}) (hHer : ProCGroups.FiniteGroupClass.Hereditary C)
    (φ : G →* H) (hφ : Continuous φ) (hφsurj : Function.Surjective φ)
    (V : CompletedGroupAlgebraIndexInClass H C) :
    Function.Surjective
      (completedGroupAlgebraFunctorialStageMapInClass
        (G := G) (H := H) C hHer (R := R) φ hφ V)
CompletedGroupAlgebra.completedGroupAlgebraFunctorialStageMapInClass_single

The functorial finite-stage map sends singleton coefficients to singleton coefficients.

Source context 11 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]
omit [TopologicalSpace R] [IsTopologicalRing R] in
theorem completedGroupAlgebraFunctorialStageMapInClass_single
    (C : ProCGroups.FiniteGroupClass.{v}) (hHer : ProCGroups.FiniteGroupClass.Hereditary C)
    (φ : G →* H) (hφ : Continuous φ) (V : CompletedGroupAlgebraIndexInClass H C)
    (q : CompletedGroupAlgebraQuotientInClass G C
      (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hHer φ hφ V)) (r : R) :
    completedGroupAlgebraFunctorialStageMapInClass
        (G := G) (H := H) C hHer (R := R) φ hφ V (MonoidAlgebra.single q r) =
      MonoidAlgebra.single
        (completedGroupAlgebraComapQuotientMapInClass (G := G) (H := H)
          C hHer φ hφ V q) r
CompletedGroupAlgebra.completedGroupAlgebraFunctorialStageMapInClass_algebraMap

The functorial finite-stage map preserves coefficient algebra-map elements.

Source context 11 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]
omit [TopologicalSpace R] [IsTopologicalRing R] in
theorem completedGroupAlgebraFunctorialStageMapInClass_algebraMap
    (C : ProCGroups.FiniteGroupClass.{v}) (hHer : ProCGroups.FiniteGroupClass.Hereditary C)
    (φ : G →* H) (hφ : Continuous φ) (V : CompletedGroupAlgebraIndexInClass H C) (r : R) :
    completedGroupAlgebraFunctorialStageMapInClass
        (G := G) (H := H) C hHer (R := R) φ hφ V
        (algebraMap R
          (CompletedGroupAlgebraStageInClass C R G
            (completedGroupAlgebraComapIndexInClass
              (G := G) (H := H) C hHer φ hφ V)) r) =
      algebraMap R (CompletedGroupAlgebraStageInClass C R H V) r
CompletedGroupAlgebra.completedGroupAlgebraStageCoeffMapInClass_comp_functorialStageMapInClass

Functorial finite-stage maps commute with coefficient change.

Source context 11 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]
omit [TopologicalSpace R] [IsTopologicalRing R] in
theorem completedGroupAlgebraStageCoeffMapInClass_comp_functorialStageMapInClass
    (C : ProCGroups.FiniteGroupClass.{v}) (hHer : ProCGroups.FiniteGroupClass.Hereditary C)
    (S : Type w) [CommRing S] (f : R →+* S)
    (φ : G →* H) (hφ : Continuous φ) (V : CompletedGroupAlgebraIndexInClass H C) :
    (completedGroupAlgebraStageCoeffMapInClass (R := R) (G := H) C S f V).comp
        (completedGroupAlgebraFunctorialStageMapInClass
          (G := G) (H := H) C hHer (R := R) φ hφ V) =
      (completedGroupAlgebraFunctorialStageMapInClass
          (G := G) (H := H) C hHer (R := S) φ hφ V).comp
        (completedGroupAlgebraStageCoeffMapInClass (R := R) (G := G) C S f
          (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hHer φ hφ V))
CompletedGroupAlgebra.continuous_completedGroupAlgebraFunctorialStageMapInClass

The functorial finite-stage group-algebra map is continuous for the finite-stage topologies.

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 continuous_completedGroupAlgebraFunctorialStageMapInClass
    (C : ProCGroups.FiniteGroupClass.{v})
    (hHer : ProCGroups.FiniteGroupClass.Hereditary C)
    (φ : G →* H) (hφ : Continuous φ) (V : CompletedGroupAlgebraIndexInClass H C) :
    letI : TopologicalSpace
        (CompletedGroupAlgebraStageInClass C R G
          (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hHer φ hφ V)) :=
      (completedGroupAlgebraSystemInClass C R G).topologicalSpace
        (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hHer φ hφ V)
    letI : TopologicalSpace (CompletedGroupAlgebraStageInClass C R H V) :=
      (completedGroupAlgebraSystemInClass C R H).topologicalSpace V
    Continuous (completedGroupAlgebraFunctorialStageMapInClass
      (G := G) (H := H) C hHer (R := R) φ hφ V) := by
  let : Finite (CompletedGroupAlgebraQuotientInClass G C
      (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hHer φ hφ V)) :=
    finite_completedGroupAlgebraQuotientInClass G C
      (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hHer φ hφ V)
  let : Finite (CompletedGroupAlgebraQuotientInClass H C V) :=
    finite_completedGroupAlgebraQuotientInClass H C V
  let : TopologicalSpace
      (CompletedGroupAlgebraStageInClass C R G
        (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hHer φ hφ V)) :=
    (completedGroupAlgebraSystemInClass C R G).topologicalSpace
      (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hHer φ hφ V)
  let : TopologicalSpace (CompletedGroupAlgebraStageInClass C R H V) :=
    (completedGroupAlgebraSystemInClass C R H).topologicalSpace V
  exact finiteGroupAlgebra_mapDomainRingHom_continuous R
    (CompletedGroupAlgebraQuotientInClass G C
      (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hHer φ hφ V))
    (CompletedGroupAlgebraQuotientInClass H C V)
    (completedGroupAlgebraComapQuotientMapInClass (G := G) (H := H) C hHer φ hφ V)
CompletedGroupAlgebra.completedGroupAlgebraFunctorialStageMapInClass_transition

Functorial finite-stage maps commute with transition maps.

Source context 11 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]
omit [TopologicalSpace R] [IsTopologicalRing R] in
theorem completedGroupAlgebraFunctorialStageMapInClass_transition
    (C : ProCGroups.FiniteGroupClass.{v}) (hHer : ProCGroups.FiniteGroupClass.Hereditary C)
    (φ : G →* H) (hφ : Continuous φ)
    {V W : CompletedGroupAlgebraIndexInClass H C} (hVW : V ≤ W) :
    (completedGroupAlgebraTransitionInClass C R H hVW).comp
        (completedGroupAlgebraFunctorialStageMapInClass
          (G := G) (H := H) C hHer (R := R) φ hφ W) =
      (completedGroupAlgebraFunctorialStageMapInClass
          (G := G) (H := H) C hHer (R := R) φ hφ V).comp
        (completedGroupAlgebraTransitionInClass C R G
          (completedGroupAlgebraComapIndexInClass_mono
            (G := G) (H := H) C hHer φ hφ hVW))
CompletedGroupAlgebra.completedGAStageCoeffMapInClass_comp_transition_comp_functorialStageMapInClass

Functorial finite-stage maps commute with a group transition followed by coefficient change.

Source context 11 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]
omit [TopologicalSpace R] [IsTopologicalRing R] in
theorem completedGAStageCoeffMapInClass_comp_transition_comp_functorialStageMapInClass
    (C : ProCGroups.FiniteGroupClass.{v}) (hHer : ProCGroups.FiniteGroupClass.Hereditary C)
    (S : Type w) [CommRing S] (f : R →+* S)
    (φ : G →* H) (hφ : Continuous φ)
    {V W : CompletedGroupAlgebraIndexInClass H C} (hVW : V ≤ W) :
    ((completedGroupAlgebraStageCoeffMapInClass (R := R) (G := H) C S f V).comp
        (completedGroupAlgebraTransitionInClass C R H hVW)).comp
        (completedGroupAlgebraFunctorialStageMapInClass
          (G := G) (H := H) C hHer (R := R) φ hφ W) =
      (completedGroupAlgebraFunctorialStageMapInClass
          (G := G) (H := H) C hHer (R := S) φ hφ V).comp
        ((completedGroupAlgebraStageCoeffMapInClass (R := R) (G := G) C S f
          (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hHer φ hφ V)).comp
          (completedGroupAlgebraTransitionInClass C R G
            (completedGroupAlgebraComapIndexInClass_mono
              (G := G) (H := H) C hHer φ hφ hVW)))
CompletedGroupAlgebra.completedGroupAlgebraFunctorialStageMapInClass_comp_stageMap

The functorial finite-stage map agrees with the stage map after passing to the comap quotient.

Source context 11 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]
omit [TopologicalSpace R] [IsTopologicalRing R] in
theorem completedGroupAlgebraFunctorialStageMapInClass_comp_stageMap
    (C : ProCGroups.FiniteGroupClass.{v}) (hHer : ProCGroups.FiniteGroupClass.Hereditary C)
    (φ : G →* H) (hφ : Continuous φ) (V : CompletedGroupAlgebraIndexInClass H C) :
    (completedGroupAlgebraFunctorialStageMapInClass
        (G := G) (H := H) C hHer (R := R) φ hφ V).comp
        (completedGroupAlgebraStageMapInClass C R G
          (completedGroupAlgebraComapIndexInClass (G := G) (H := H) C hHer φ hφ V)) =
      (completedGroupAlgebraStageMapInClass C R H V).comp
        (MonoidAlgebra.mapDomainRingHom R φ)