Module

Coordinates.lean

Nyll.ProCGroups.FoxDifferential.Completed.ProCIntegerCoefficients.FreeGroup.Coordinates
12 declarations indexed from sourceView source ↗

Fox differential: completed — \(\mathbb{Z}_C\) coefficients — free group — coordinates

The principal declarations in this module are:

  • zcFreeGroupFoxBoundary

The completed Fox boundary/Euler map \(v \mapsto \sum_i v_i * ([\psi(x_i)]-1)\).

  • zcDifferentialToFreeFoxCoordinates

The linear map from the completed universal module to completed Fox-coordinate vectors.

  • zcFreeGroupFoxBoundary_apply

The boundary map is evaluated on the canonical generators and then extended linearly to the completed coordinate module.

  • zcFreeGroupFoxBoundary_eq_foxBoundaryMap

The completed Fox boundary is the generic finite Fox boundary map specialized to \(x \mapsto [\psi(x)] - 1\).

Declarations

FoxDifferential.zcFreeGroupFoxBoundary

The completed Fox boundary/Euler map \(v \mapsto \sum_i v_i * ([\psi(x_i)]-1)\).

Source context 9 commands

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

namespace FoxDifferential
noncomputable section
open scoped BigOperators
universe u v
variable (C : ProCGroups.FiniteGroupClass.{v})
variable {X : Type u} [DecidableEq X]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
section FiniteBasis
variable [Fintype X]
def zcFreeGroupFoxBoundary (ψ : FreeGroup X →* H) :
    ZCFreeFoxCoordinates C (X := X) (H := H) →ₗ[ZCCompletedGroupAlgebra C H]
      ZCCompletedGroupAlgebra C H where
  toFun v := ∑ i : X, v i * (zcGroupLike C H (ψ (FreeGroup.of i)) - 1)
  map_add' := by
    intro v w
    simp only [Pi.add_apply, add_mul, Finset.sum_add_distrib]
  map_smul' := by
    intro r v
    simp only [Pi.smul_apply, smul_eq_mul, mul_assoc, RingHom.id_apply, Finset.mul_sum]
FoxDifferential.zcFreeGroupFoxBoundary_apply

The boundary map is evaluated on the canonical generators and then extended linearly to the completed coordinate module.

Source context 10 commands

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

namespace FoxDifferential
noncomputable section
open scoped BigOperators
universe u v
variable (C : ProCGroups.FiniteGroupClass.{v})
variable {X : Type u} [DecidableEq X]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
section FiniteBasis
variable [Fintype X]
omit [DecidableEq X] in
theorem zcFreeGroupFoxBoundary_apply
    (ψ : FreeGroup X →* H) (v : ZCFreeFoxCoordinates C (X := X) (H := H)) :
    zcFreeGroupFoxBoundary C ψ v =
      ∑ i : X, v i * (zcGroupLike C H (ψ (FreeGroup.of i)) - 1)
FoxDifferential.zcFreeGroupFoxBoundary_eq_foxBoundaryMap

The completed Fox boundary is the generic finite Fox boundary map specialized to \(x \mapsto [\psi(x)] - 1\).

Source context 10 commands

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

namespace FoxDifferential
noncomputable section
open scoped BigOperators
universe u v
variable (C : ProCGroups.FiniteGroupClass.{v})
variable {X : Type u} [DecidableEq X]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
section FiniteBasis
variable [Fintype X]
omit [DecidableEq X] in
theorem zcFreeGroupFoxBoundary_eq_foxBoundaryMap
    (ψ : FreeGroup X →* H) :
    zcFreeGroupFoxBoundary C ψ =
      foxBoundaryMap
        (fun i : X =>
          coefficientFoxBoundary (zcCompletedGroupAlgebraScalar C ψ) (FreeGroup.of i)) := by
  ext v
  rfl
FoxDifferential.zcFreeGroupFoxBoundary_single

The completed Fox boundary sends a coordinate basis vector to the corresponding completed augmentation generator.

Source context 9 commands

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

namespace FoxDifferential
noncomputable section
open scoped BigOperators
universe u v
variable (C : ProCGroups.FiniteGroupClass.{v})
variable {X : Type u} [DecidableEq X]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
section FiniteBasis
variable [Fintype X]
theorem zcFreeGroupFoxBoundary_single (ψ : FreeGroup X →* H) (i : X) :
    zcFreeGroupFoxBoundary C ψ
        (Pi.single i (1 : ZCCompletedGroupAlgebra C H)) =
      zcCompletedGroupAlgebraBoundary C ψ (FreeGroup.of i)
FoxDifferential.zcDifferentialToFreeFoxCoordinates

The linear map from the completed universal module to completed Fox-coordinate vectors.

Source context 9 commands

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

namespace FoxDifferential
noncomputable section
open scoped BigOperators
universe u v
variable (C : ProCGroups.FiniteGroupClass.{v})
variable {X : Type u} [DecidableEq X]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
section FiniteBasis
variable [Fintype X]
def zcDifferentialToFreeFoxCoordinates (ψ : FreeGroup X →* H) :
    ZCCompletedDifferentialModule C ψ →ₗ[ZCCompletedGroupAlgebra C H]
      ZCFreeFoxCoordinates C (X := X) (H := H)
FoxDifferential.zcDifferentialToFreeFoxCoordinates_universal

The completed coordinate map sends a universal differential to the completed Fox derivative vector.

Source context 10 commands

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

namespace FoxDifferential
noncomputable section
open scoped BigOperators
universe u v
variable (C : ProCGroups.FiniteGroupClass.{v})
variable {X : Type u} [DecidableEq X]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
section FiniteBasis
variable [Fintype X]
omit [Fintype X] in
theorem zcDifferentialToFreeFoxCoordinates_universal
    (ψ : FreeGroup X →* H) (w : FreeGroup X) :
    zcDifferentialToFreeFoxCoordinates C ψ
        (zcUniversalDifferential C ψ w) =
      zcFreeGroupFoxDerivativeVector C ψ w
FoxDifferential.zcFreeFoxCoordinatesLinearMap

The linear map from completed Fox-coordinate vectors to the completed universal module, sending the coordinate basis at \(x\) to \(d_{\psi}(x)\).

Source context 9 commands

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

namespace FoxDifferential
noncomputable section
open scoped BigOperators
universe u v
variable (C : ProCGroups.FiniteGroupClass.{v})
variable {X : Type u} [DecidableEq X]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
section FiniteBasis
variable [Fintype X]
def zcFreeFoxCoordinatesLinearMap (ψ : FreeGroup X →* H) :
    ZCFreeFoxCoordinates C (X := X) (H := H) →ₗ[ZCCompletedGroupAlgebra C H]
      ZCCompletedDifferentialModule C ψ where
  toFun v := ∑ x : X, v x • zcUniversalDifferential C ψ (FreeGroup.of x)
  map_add' := by
    intro v w
    simp only [Pi.add_apply, add_smul, Finset.sum_add_distrib]
  map_smul' := by
    intro r v
    simp only [Pi.smul_apply, RingHom.id_apply, smul_eq_mul, Finset.smul_sum, smul_smul]
FoxDifferential.zcFreeFoxCoordinatesLinearMap_single

The coordinate-to-differential map sends a coordinate basis vector to the corresponding universal completed differential.

Source context 9 commands

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

namespace FoxDifferential
noncomputable section
open scoped BigOperators
universe u v
variable (C : ProCGroups.FiniteGroupClass.{v})
variable {X : Type u} [DecidableEq X]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
section FiniteBasis
variable [Fintype X]
theorem zcFreeFoxCoordinatesLinearMap_single (ψ : FreeGroup X →* H) (x : X) :
    zcFreeFoxCoordinatesLinearMap C ψ
        (Pi.single x (1 : ZCCompletedGroupAlgebra C H)) =
      zcUniversalDifferential C ψ (FreeGroup.of x)
FoxDifferential.zcFreeFoxCoordinatesLinearMap_derivativeVector

The coordinate-to-differential map recovers the universal completed differential from the completed derivative vector.

Source context 9 commands

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

namespace FoxDifferential
noncomputable section
open scoped BigOperators
universe u v
variable (C : ProCGroups.FiniteGroupClass.{v})
variable {X : Type u} [DecidableEq X]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
section FiniteBasis
variable [Fintype X]
theorem zcFreeFoxCoordinatesLinearMap_derivativeVector
    (ψ : FreeGroup X →* H) (w : FreeGroup X) :
    zcFreeFoxCoordinatesLinearMap C ψ
        (zcFreeGroupFoxDerivativeVector C ψ w) =
      zcUniversalDifferential C ψ w
FoxDifferential.zcDifferentialToFreeFoxCoordinates_comp_zcFreeFoxCoordinatesLinearMap

The coordinate map is a left inverse to the coordinate-to-differential map.

Source context 9 commands

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

namespace FoxDifferential
noncomputable section
open scoped BigOperators
universe u v
variable (C : ProCGroups.FiniteGroupClass.{v})
variable {X : Type u} [DecidableEq X]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
section FiniteBasis
variable [Fintype X]
theorem zcDifferentialToFreeFoxCoordinates_comp_zcFreeFoxCoordinatesLinearMap
    (ψ : FreeGroup X →* H) :
    (zcDifferentialToFreeFoxCoordinates C ψ).comp
        (zcFreeFoxCoordinatesLinearMap C ψ) =
      LinearMap.id
FoxDifferential.zcFreeFoxCoordinatesLinearMap_comp_zcDifferentialToFreeFoxCoordinates

The coordinate-to-differential map is a left inverse to the completed coordinate map.

Source context 9 commands

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

namespace FoxDifferential
noncomputable section
open scoped BigOperators
universe u v
variable (C : ProCGroups.FiniteGroupClass.{v})
variable {X : Type u} [DecidableEq X]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
section FiniteBasis
variable [Fintype X]
theorem zcFreeFoxCoordinatesLinearMap_comp_zcDifferentialToFreeFoxCoordinates
    (ψ : FreeGroup X →* H) :
    (zcFreeFoxCoordinatesLinearMap C ψ).comp
        (zcDifferentialToFreeFoxCoordinates C ψ) =
      LinearMap.id
FoxDifferential.zcFreeFoxCoordinatesLinearEquivDifferential

The linear equivalence between completed Fox coordinates and the completed universal differential module of a finite-rank free group.

Source context 9 commands

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

namespace FoxDifferential
noncomputable section
open scoped BigOperators
universe u v
variable (C : ProCGroups.FiniteGroupClass.{v})
variable {X : Type u} [DecidableEq X]
variable {H : Type v} [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
section FiniteBasis
variable [Fintype X]
def zcFreeFoxCoordinatesLinearEquivDifferential
    (ψ : FreeGroup X →* H) :
    ZCFreeFoxCoordinates C (X := X) (H := H) ≃ₗ[ZCCompletedGroupAlgebra C H]
      ZCCompletedDifferentialModule C ψ