OAI/GroupTheory/Kervaire/RegularOperators.lean

GitHub source file

40 declarations, 0 contain sorry, 0 declared as axioms

  1. theorem OAI.KervaireRegular.mem_l2_reindex line 23

    Source documentation

    Permuting the coordinates of a square-summable family preserves membership, without requiring a countable set of coordinates.

    theorem mem_l2_reindex (e : α ≃ β) (f : ℓ²(α, ℂ)) :
        Memℓp (fun j => f (e.symm j)) 2 := by
    …
  2. def OAI.KervaireRegular.reindexLinear line 29

    Source documentation

    Coordinate permutation before adding the isometric structure.

    def reindexLinear (e : α ≃ β) : ℓ²(α, ℂ) ≃ₗ[ℂ] ℓ²(β, ℂ) where
    …
  3. theorem OAI.KervaireRegular.reindexLinear_apply line 37
  4. def OAI.KervaireRegular.reindex line 41

    Source documentation

    The unitary permutation representation on ℓ², for arbitrary index types.

    def reindex (e : α ≃ β) : ℓ²(α, ℂ) ≃ₗᵢ[ℂ] ℓ²(β, ℂ) :=
    …
  5. theorem OAI.KervaireRegular.reindex_apply line 47
  6. theorem OAI.KervaireRegular.reindex_symm line 50
  7. theorem OAI.KervaireRegular.reindex_trans line 54
  8. def OAI.KervaireRegular.delta line 60

    Source documentation

    The standard delta vector used for the finite trace.

    def delta (i : α) : ℓ²(α, ℂ) := by classical exact lp.single 2 i 1
  9. theorem OAI.KervaireRegular.reindex_delta line 62
  10. theorem OAI.KervaireRegular.inner_delta_left line 68
  11. theorem OAI.KervaireRegular.inner_delta_right line 73
  12. def OAI.KervaireRegular.left line 81

    Source documentation

    L(a) δ_x = δ_(ax) including infinite and uncountable groups.

    def left (a : A) : ℓ²(A, ℂ) ≃ₗᵢ[ℂ] ℓ²(A, ℂ) := reindex (Equiv.mulLeft a)

    Mentions: OAI.KervaireRegular.reindex

  13. def OAI.KervaireRegular.right line 83
  14. theorem OAI.KervaireRegular.left_apply line 85
  15. theorem OAI.KervaireRegular.right_apply line 88
  16. theorem OAI.KervaireRegular.left_delta line 91
  17. theorem OAI.KervaireRegular.right_delta line 94
  18. theorem OAI.KervaireRegular.left_mul line 97
  19. theorem OAI.KervaireRegular.right_mul line 100
  20. theorem OAI.KervaireRegular.left_right line 104

    Source documentation

    The commuting left and right regular actions.

    theorem left_right (a b : A) (f : ℓ²(A, ℂ)) :
        left a (right b f) = right b (left a f) := by ext x; simp [mul_assoc]

    Mentions: OAI.KervaireRegular.left, OAI.KervaireRegular.right

  21. abbrev OAI.KervaireRegular.Operator line 107
  22. instance OAI.KervaireRegular.operator_real_smulCommClass line 109
  23. instance OAI.KervaireRegular.operator_real_isScalarTower line 112
  24. def OAI.KervaireRegular.InCommutant line 116

    Source documentation

    The commutant of the right regular representation.

    def InCommutant (T : Operator A) : Prop :=
    …

    Mentions: OAI.KervaireRegular.Operator

  25. theorem OAI.KervaireRegular.right_star line 119
  26. theorem OAI.KervaireRegular.right_one line 125
  27. theorem OAI.KervaireRegular.apply_delta_eq_right line 130

    Source documentation

    Translation equivariance determines every matrix coefficient from one column.

    theorem apply_delta_eq_right {T : Operator A} (hT : InCommutant T) (y : A) :
        T (delta y) = right y⁻¹ (T (delta 1)) := by
    …

    Mentions: OAI.KervaireRegular.Operator, OAI.KervaireRegular.InCommutant, OAI.KervaireRegular.delta, OAI.KervaireRegular.right

  28. theorem OAI.KervaireRegular.matrix_coefficient line 135
  29. def OAI.KervaireRegular.trace line 140

    Source documentation

    The (unnormalized for one copy) vector trace.

    def trace : Operator A →L[ℂ] ℂ :=
    …

    Mentions: OAI.KervaireRegular.Operator

  30. theorem OAI.KervaireRegular.trace_apply line 143
  31. theorem OAI.KervaireRegular.trace_eq_coefficient line 146
  32. theorem OAI.KervaireRegular.trace_one line 149
  33. theorem OAI.KervaireRegular.star_coefficient line 154

    Source documentation

    The reflected coefficient identity needed to evaluate a product trace.

    theorem star_coefficient {T : Operator A} (hT : InCommutant T) (x : A) :
        star (star T (delta 1) x) = T (delta 1) x⁻¹ := by
    …

    Mentions: OAI.KervaireRegular.Operator, OAI.KervaireRegular.InCommutant, OAI.KervaireRegular.delta

  34. theorem OAI.KervaireRegular.trace_mul_eq_tsum line 164
  35. theorem OAI.KervaireRegular.trace_mul_comm line 175

    Source documentation

    Cyclicity uses a bijection of the entire index set; countability is unnecessary.

    theorem trace_mul_comm {S T : Operator A} (hS : InCommutant S) (hT : InCommutant T) :
        trace (S * T) = trace (T * S) := by
    …

    Mentions: OAI.KervaireRegular.Operator, OAI.KervaireRegular.InCommutant, OAI.KervaireRegular.trace

  36. theorem OAI.KervaireRegular.eq_zero_of_delta_one line 186

    Source documentation

    The vector at the identity is separating for the right regular commutant.

    theorem eq_zero_of_delta_one {T : Operator A} (hT : InCommutant T)
        (h : T (delta 1) = 0) : T = 0 := by
    …

    Mentions: OAI.KervaireRegular.Operator, OAI.KervaireRegular.InCommutant, OAI.KervaireRegular.delta

  37. theorem OAI.KervaireRegular.trace_star_mul_self_eq_zero_iff line 202

    Source documentation

    Faithfulness in positive-square form, the part needed for positive operators.

    theorem trace_star_mul_self_eq_zero_iff {T : Operator A} (hT : InCommutant T) :
        trace (star T * T) = 0 ↔ T = 0 := by
    …

    Mentions: OAI.KervaireRegular.Operator, OAI.KervaireRegular.InCommutant, OAI.KervaireRegular.trace

  38. theorem OAI.KervaireRegular.InCommutant.sqrt line 218

    Source documentation

    The commutant is closed under the nonnegative continuous square root.

    theorem InCommutant.sqrt {T : Operator A} (hT : InCommutant T) :
        InCommutant (CFC.sqrt T) := by
    …

    Mentions: OAI.KervaireRegular.Operator, OAI.KervaireRegular.InCommutant

  39. theorem OAI.KervaireRegular.trace_nonneg line 224

    Source documentation

    Positivity of the vector functional.

    theorem trace_nonneg {T : Operator A} (hT : 0 ≤ T) : 0 ≤ (trace T).re :=
    …

    Mentions: OAI.KervaireRegular.Operator, OAI.KervaireRegular.trace

  40. theorem OAI.KervaireRegular.trace_eq_zero_iff_of_nonneg line 228

    Source documentation

    Faithfulness for every nonnegative operator in the commutant.

    theorem trace_eq_zero_iff_of_nonneg {T : Operator A} (hT : InCommutant T)
        (hpos : 0 ≤ T) : trace T = 0 ↔ T = 0 := by
    …

    Mentions: OAI.KervaireRegular.Operator, OAI.KervaireRegular.InCommutant, OAI.KervaireRegular.trace