OAI/GroupTheory/Kervaire/RegularOperators.lean
40 declarations, 0 contain sorry, 0 declared as axioms
- theorem
OAI.KervaireRegular.mem_l2_reindexline 23Source 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 … - def
OAI.KervaireRegular.reindexLinearline 29Source documentation
Coordinate permutation before adding the isometric structure.
def reindexLinear (e : α ≃ β) : ℓ²(α, ℂ) ≃ₗ[ℂ] ℓ²(β, ℂ) where …
- theorem
OAI.KervaireRegular.reindexLinear_applyline 37 - def
OAI.KervaireRegular.reindexline 41Source documentation
The unitary permutation representation on
ℓ², for arbitrary index types.def reindex (e : α ≃ β) : ℓ²(α, ℂ) ≃ₗᵢ[ℂ] ℓ²(β, ℂ) := …
- theorem
OAI.KervaireRegular.reindex_applyline 47 - theorem
OAI.KervaireRegular.reindex_symmline 50 - theorem
OAI.KervaireRegular.reindex_transline 54 - def
OAI.KervaireRegular.deltaline 60Source 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
- theorem
OAI.KervaireRegular.reindex_deltaline 62 - theorem
OAI.KervaireRegular.inner_delta_leftline 68 - theorem
OAI.KervaireRegular.inner_delta_rightline 73 - def
OAI.KervaireRegular.leftline 81Source 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
- def
OAI.KervaireRegular.rightline 83 - theorem
OAI.KervaireRegular.left_applyline 85 - theorem
OAI.KervaireRegular.right_applyline 88 - theorem
OAI.KervaireRegular.left_deltaline 91 - theorem
OAI.KervaireRegular.right_deltaline 94 - theorem
OAI.KervaireRegular.left_mulline 97 - theorem
OAI.KervaireRegular.right_mulline 100 - theorem
OAI.KervaireRegular.left_rightline 104Source 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
- abbrev
OAI.KervaireRegular.Operatorline 107 - instance
OAI.KervaireRegular.operator_real_smulCommClassline 109 - instance
OAI.KervaireRegular.operator_real_isScalarTowerline 112 - def
OAI.KervaireRegular.InCommutantline 116Source documentation
The commutant of the right regular representation.
def InCommutant (T : Operator A) : Prop := …
Mentions: OAI.KervaireRegular.Operator
- theorem
OAI.KervaireRegular.right_starline 119 - theorem
OAI.KervaireRegular.right_oneline 125 - theorem
OAI.KervaireRegular.apply_delta_eq_rightline 130Source 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
- theorem
OAI.KervaireRegular.matrix_coefficientline 135 - def
OAI.KervaireRegular.traceline 140Source documentation
The (unnormalized for one copy) vector trace.
def trace : Operator A →L[ℂ] ℂ := …
Mentions: OAI.KervaireRegular.Operator
- theorem
OAI.KervaireRegular.trace_applyline 143 - theorem
OAI.KervaireRegular.trace_eq_coefficientline 146 - theorem
OAI.KervaireRegular.trace_oneline 149 - theorem
OAI.KervaireRegular.star_coefficientline 154Source 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
- theorem
OAI.KervaireRegular.trace_mul_eq_tsumline 164 - theorem
OAI.KervaireRegular.trace_mul_commline 175Source 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
- theorem
OAI.KervaireRegular.eq_zero_of_delta_oneline 186Source 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
- theorem
OAI.KervaireRegular.trace_star_mul_self_eq_zero_iffline 202Source 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
- theorem
OAI.KervaireRegular.InCommutant.sqrtline 218Source 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
- theorem
OAI.KervaireRegular.trace_nonnegline 224Source 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
- theorem
OAI.KervaireRegular.trace_eq_zero_iff_of_nonnegline 228Source 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