openAI-math-dataset / lean /OAI /Analysis /IrrationalRotation /Operators /InvariantTraceTransport.lean
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Add lean source and binary files (part 19)
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import OAI.Analysis.IrrationalRotation.Operators.NormalTraceProjectionRigidity
namespace OAI
noncomputable section
namespace Invariant233
variable {H : Type*} [NormedAddCommGroup H] [InnerProductSpace ℂ H]
[CompleteSpace H]
theorem NormalTraceProjectionRigidity.hasOnlyTrivialInvariantProjections_smul_iff
(M : VonNeumannAlgebra H)
(T : H →L[ℂ] H) {c : ℂ} (hc : c ≠ 0) :
HasOnlyTrivialInvariantProjections M (c • T) ↔
HasOnlyTrivialInvariantProjections M T := by
have hinv (p : H →L[ℂ] H) : (1 - p) * (c • T) * p = 0 ↔
(1 - p) * T * p = 0 := by
simp only [mul_smul_comm, smul_mul_assoc, smul_eq_zero, hc, false_or]
constructor
· intro h p hpm hp hT
exact h p hpm hp ((hinv p).mpr hT)
· intro h p hpm hp hT
exact h p hpm hp ((hinv p).mp hT)
theorem hasOnlyTrivialInvariantProjections_of_trace_transport
(M : VonNeumannAlgebra H) (τ : TracialState M)
(hτ : IsNormalFaithfulTracialState M τ) (A B : M)
(hB : HasOnlyTrivialInvariantProjections M (B : H →L[ℂ] H))
(htransport : ∀ p : M, IsStarProjection (p : H →L[ℂ] H) →
(1 - (p : H →L[ℂ] H)) * (A : H →L[ℂ] H) * (p : H →L[ℂ] H) = 0 →
∃ P : M, IsStarProjection (P : H →L[ℂ] H) ∧
(1 - (P : H →L[ℂ] H)) * (B : H →L[ℂ] H) * (P : H →L[ℂ] H) = 0 ∧
τ P = τ p) :
HasOnlyTrivialInvariantProjections M (A : H →L[ℂ] H) := by
intro p hpm hp hinv
let p' : M := ⟨p, hpm⟩
obtain ⟨P, hP, hPinv, htrace⟩ := htransport p' hp hinv
have htrivP := hB (P : H →L[ℂ] H) P.property hP hPinv
have hnontriv := NormalTraceProjectionRigidity.nontrivial_iff_of_trace_eq
τ hτ hp hP htrace.symm
by_contra hpnontriv
push Not at hpnontriv
have hp' : p' ≠ 0 ∧ p' ≠ 1 := by
constructor
· intro h
exact hpnontriv.1 (congrArg Subtype.val h)
· intro h
exact hpnontriv.2 (congrArg Subtype.val h)
have hP' := hnontriv.mp hp'
rcases htrivP with hz | ho
· exact hP'.1 (Subtype.ext hz)
· exact hP'.2 (Subtype.ext ho)
end Invariant233
end
end OAI