Module

Topology.lean

Nyll.ProCGroups.CompletedGroupAlgebra.Basic.InClass.Topology
10 declarations indexed from sourceView source ↗

Completed Group Algebra / Basic / Within a Class / Topology

This module transports finite-stage topological structures through the named \(C\)-indexed inverse-limit carrier and records its compactness and separation properties.

Declarations

Source context 9 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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Ring ((completedGroupAlgebraSystemInClass C R G).X U)
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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Ring ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Ring (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Module R ((completedGroupAlgebraSystemInClass C R G).X U)
CompletedGroupAlgebra.completedGroupAlgebraStageInClass_isTopologicalRing

Each \(C\)-indexed finite stage is a topological ring.

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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Ring ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Ring (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Module R ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Module R (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
theorem completedGroupAlgebraStageInClass_isTopologicalRing
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    letI : Finite (CompletedGroupAlgebraQuotientInClass G C U) :=
      finite_completedGroupAlgebraQuotientInClass G C U
    letI : TopologicalSpace (CompletedGroupAlgebraStageInClass C R G U) :=
      (completedGroupAlgebraSystemInClass C R G).topologicalSpace U
    IsTopologicalRing (CompletedGroupAlgebraStageInClass C R G U) := by
  let : Finite (CompletedGroupAlgebraQuotientInClass G C U) :=
    finite_completedGroupAlgebraQuotientInClass G C U
  let : TopologicalSpace (CompletedGroupAlgebraStageInClass C R G U) :=
    (completedGroupAlgebraSystemInClass C R G).topologicalSpace U
  dsimp [completedGroupAlgebraSystemInClass, CompletedGroupAlgebraStageInClass]
  exact finiteGroupAlgebra_isTopologicalRing R (CompletedGroupAlgebraQuotientInClass G C U)
CompletedGroupAlgebra.instIsTopologicalRingCompletedGroupAlgebraSystemInClassX

The inverse system of finite-stage group algebras inherits a ring structure from the compatible finite-stage rings.

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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Ring ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Ring (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Module R ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Module R (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
instance instIsTopologicalRingCompletedGroupAlgebraSystemInClassX
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    IsTopologicalRing ((completedGroupAlgebraSystemInClass C R G).X U)
CompletedGroupAlgebra.instIsTopologicalRingCompletedGroupAlgebraInClass

The \(C\)-indexed completed group algebra inherits a ring structure from the compatible finite-stage rings.

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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Ring ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Ring (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Module R ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Module R (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
instance instIsTopologicalRingCompletedGroupAlgebraInClass
    (C : ProCGroups.FiniteGroupClass.{v}) :
    IsTopologicalRing (CompletedGroupAlgebraInClass C R G)
CompletedGroupAlgebra.instContinuousSMulCompletedGroupAlgebraInClass

Scalar multiplication is continuous for the relevant inverse-limit topology.

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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Ring ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Ring (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Module R ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Module R (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
instance instContinuousSMulCompletedGroupAlgebraInClass
    (C : ProCGroups.FiniteGroupClass.{v}) :
    ContinuousSMul R (CompletedGroupAlgebraInClass C R G)
CompletedGroupAlgebra.continuous_completedGroupAlgebraAlgebraMapInClass

The coefficient-ring map into the \(C\)-indexed completed group algebra is continuous.

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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Ring ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Ring (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Module R ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Module R (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
theorem continuous_completedGroupAlgebraAlgebraMapInClass
    (C : ProCGroups.FiniteGroupClass.{v}) :
    Continuous (algebraMap R (CompletedGroupAlgebraInClass C R G))
CompletedGroupAlgebra.completedGroupAlgebraInClass_compactSpace

The \(C\)-indexed completed group algebra is compact for compact Hausdorff 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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Ring ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Ring (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Module R ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Module R (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
theorem completedGroupAlgebraInClass_compactSpace
    (C : ProCGroups.FiniteGroupClass.{v})
    [CompactSpace R] [T2Space R] :
    CompactSpace (CompletedGroupAlgebraInClass C R G)
CompletedGroupAlgebra.completedGroupAlgebraInClass_t2Space

The \(C\)-indexed completed group algebra is Hausdorff for Hausdorff 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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Ring ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Ring (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Module R ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Module R (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
theorem completedGroupAlgebraInClass_t2Space
    (C : ProCGroups.FiniteGroupClass.{v})
    [T2Space R] :
    T2Space (CompletedGroupAlgebraInClass C R G)
CompletedGroupAlgebra.completedGroupAlgebraInClass_totallyDisconnectedSpace

The \(C\)-indexed completed group algebra is totally disconnected for totally disconnected 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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Ring ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Ring (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
local instance
    (C : ProCGroups.FiniteGroupClass.{v})
    (U : CompletedGroupAlgebraIndexInClass G C) :
    Module R ((completedGroupAlgebraSystemInClass C R G).X U) := by
  change Module R (CompletedGroupAlgebraStageInClass C R G U)
  infer_instance
theorem completedGroupAlgebraInClass_totallyDisconnectedSpace
    (C : ProCGroups.FiniteGroupClass.{v})
    [TotallyDisconnectedSpace R] :
    TotallyDisconnectedSpace (CompletedGroupAlgebraInClass C R G)