Module

OpenSubmoduleQuotient.lean

Nyll.ProCGroups.CompletedGroupAlgebra.UniversalProperty.OpenSubmoduleQuotient
6 declarations indexed from sourceView source ↗

Lifts to open-submodule quotients

The finite-quotient universal property yields a unique continuous linear lift to the quotient of a profinite module by an open submodule. This file constructs the lift and records its value on group-like generators and its factorization formula.

Declarations

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
open ProCGroups.Completion
universe u v w
variable (R : ProfiniteCommRing.{u})
variable (G : ProfiniteGrp.{v})
instance (N : ProfiniteModule.{u, w} R.toProfiniteRing) : Module R N
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
open ProCGroups.Completion
universe u v w
variable (R : ProfiniteCommRing.{u})
variable (G : ProfiniteGrp.{v})
local instance (N : ProfiniteModule.{u, w} R.toProfiniteRing) : Module R N :=
  N.module
instance (N : ProfiniteModule.{u, w} R.toProfiniteRing) :
    ContinuousSMul R N
CompletedGroupAlgebra.completedGroupAlgebra_existsUnique_lift_to_openSubmoduleQuotient

The quotient-target form of the existence step in Lemma 5.3.5(d): after quotienting a profinite target module by an open submodule, the prescribed continuous map from \(G\) extends uniquely from \(\widehat{R[G]}\).

Source context 12 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
open ProCGroups.Completion
universe u v w
variable (R : ProfiniteCommRing.{u})
variable (G : ProfiniteGrp.{v})
local instance (N : ProfiniteModule.{u, w} R.toProfiniteRing) : Module R N :=
  N.module
local instance (N : ProfiniteModule.{u, w} R.toProfiniteRing) :
    ContinuousSMul R N :=
  N.continuousSMul
theorem completedGroupAlgebra_existsUnique_lift_to_openSubmoduleQuotient
    (N : ProfiniteModule.{u, w} R.toProfiniteRing)
    (f : G → N) (hf : Continuous f)
    (W : Submodule R N) (hW : IsOpen (W : Set N)) :
    ∃! F : CompletedGroupAlgebraCarrier R G →L[R] N ⧸ W,
      ∀ g : G, F (completedGroupAlgebraOf R G g) = Submodule.mkQ W (f g)
CompletedGroupAlgebra.completedGroupAlgebraLiftToOpenSubmoduleQuotient

The chosen quotient-valued extension attached to an open submodule of a profinite target.

Source context 12 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
open ProCGroups.Completion
universe u v w
variable (R : ProfiniteCommRing.{u})
variable (G : ProfiniteGrp.{v})
local instance (N : ProfiniteModule.{u, w} R.toProfiniteRing) : Module R N :=
  N.module
local instance (N : ProfiniteModule.{u, w} R.toProfiniteRing) :
    ContinuousSMul R N :=
  N.continuousSMul
def completedGroupAlgebraLiftToOpenSubmoduleQuotient
    (N : ProfiniteModule.{u, w} R.toProfiniteRing)
    (f : G → N) (hf : Continuous f)
    (W : Submodule R N) (hW : IsOpen (W : Set N)) :
    CompletedGroupAlgebraCarrier R G →L[R] N ⧸ W
CompletedGroupAlgebra.completedGroupAlgebraLiftToOpenSubmoduleQuotient_apply_of

The quotient-valued lift has the prescribed value on completed group-like elements.

Source context 12 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
open ProCGroups.Completion
universe u v w
variable (R : ProfiniteCommRing.{u})
variable (G : ProfiniteGrp.{v})
local instance (N : ProfiniteModule.{u, w} R.toProfiniteRing) : Module R N :=
  N.module
local instance (N : ProfiniteModule.{u, w} R.toProfiniteRing) :
    ContinuousSMul R N :=
  N.continuousSMul
theorem completedGroupAlgebraLiftToOpenSubmoduleQuotient_apply_of
    (N : ProfiniteModule.{u, w} R.toProfiniteRing)
    (f : G → N) (hf : Continuous f)
    (W : Submodule R N) (hW : IsOpen (W : Set N)) (g : G) :
    completedGroupAlgebraLiftToOpenSubmoduleQuotient
        (R := R) (G := G) N f hf W hW
        (completedGroupAlgebraOf R G g) =
      Submodule.mkQ W (f g)
CompletedGroupAlgebra.completedGroupAlgebraLiftToOpenSubmoduleQuotient_factor

The quotient-valued extensions are compatible with refinement of open submodules.

Source context 12 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
open ProCGroups.Completion
universe u v w
variable (R : ProfiniteCommRing.{u})
variable (G : ProfiniteGrp.{v})
local instance (N : ProfiniteModule.{u, w} R.toProfiniteRing) : Module R N :=
  N.module
local instance (N : ProfiniteModule.{u, w} R.toProfiniteRing) :
    ContinuousSMul R N :=
  N.continuousSMul
theorem completedGroupAlgebraLiftToOpenSubmoduleQuotient_factor
    (N : ProfiniteModule.{u, w} R.toProfiniteRing)
    (f : G → N) (hf : Continuous f)
    {W V : Submodule R N} (hWV : W ≤ V)
    (hW : IsOpen (W : Set N)) (hV : IsOpen (V : Set N))
    (x : CompletedGroupAlgebraCarrier R G) :
    Submodule.factor hWV
        (completedGroupAlgebraLiftToOpenSubmoduleQuotient
          (R := R) (G := G) N f hf W hW x) =
      completedGroupAlgebraLiftToOpenSubmoduleQuotient
        (R := R) (G := G) N f hf V hV x