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Project-declaredLean 4.28.0 · mathlib@8f9d9cff6bd7

Trace Right pure MES

traceRight_pure_MES

Plain-language statement

Entanglement of Formation of bipartite systems. It is the convex roof extension of the von Neumann entropy of one of the subsystems (here chosen to be the left one, but see Entropy.Sᵥₙ_of_partial_eq). The function Sᵥₙ ∘ traceRight ∘ pure is phase-invariant because pure maps phase-equivalent kets to the same mixed state, so it descends to `KetUpToPha...

Exact Lean statement

theorem traceRight_pure_MES (d : Type*) [Fintype d] [DecidableEq d] [Nonempty d] :
    (MState.pure (Ket.MES d)).traceRight = MState.uniform

Formal artifact

Lean source

Canonical source
Full Lean sourceLean 4
theorem traceRight_pure_MES (d : Type*) [Fintype d] [DecidableEq d] [Nonempty d] :    (MState.pure (Ket.MES d)).traceRight = MState.uniform := by  -- By definition of partial trace, we sum over the second system.  have h_partial_trace :  (i j : d), ∑ k : d, (Ket.MES d).vec (i, k) * (star (Ket.MES d).vec (j, k)) = (1 / Fintype.card d : ) * (if i = j then 1 else 0) := by    unfold Ket.MES    intro i j    simp only [one_div, Pi.star_apply, RCLike.star_def, ite_mul, zero_mul, Finset.sum_ite_eq,      Finset.mem_univ, ↓reduceIte, Complex.ofReal_inv]    split    · subst i      simp only [map_inv₀, Complex.conj_ofReal]      ring_nf; norm_cast; norm_num;    · grind  unfold MState.pure MState.traceRight MState.uniform  ext i j  convert h_partial_trace i j  simp_all only [Pi.star_apply, RCLike.star_def, one_div, Complex.ofReal_inv,    Complex.ofReal_natCast, mul_ite, mul_one, mul_zero, HermitianMat.mat_apply,    coe_ofClassical, ProbDistribution.uniform_def, Finset.card_univ]  unfold HermitianMat.diagonal  simp_all only [map_inv₀, map_natCast]  rfl
Project
quantumInfo
License
MIT
Commit
56e83a9288a3
Source
QuantumInfo/Finite/Entanglement.lean:223-244

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Project documentation

The operator norm of the conjugate transpose is equal to the operator norm. -/ theorem Matrix.opNorm_conjTranspose_eq_opNorm {m n : Type*} [Fintype m] [Fintype n] [DecidableEq m] [DecidableEq n] (A : Matrix m n 𝕜) : Matrix.opNorm Aᴴ = Matrix.opNorm A := by unfold Matrix.opNorm rw [← ContinuousLinearMap.adjoint.norm_map (toEuclideanLin A).toContinuousLine...

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Person-level attribution pending.

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Plain-language statement

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Source project: quantumInfo

Person-level attribution pending.

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Plain-language statement

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Source project: quantumInfo

Person-level attribution pending.

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