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Project-declaredLean 4.28.0 · mathlib@8f9d9cff6bd7

F alpha at optimizer

f_alpha_at_optimizer

Project documentation

Sub-lemma for Step 1b: the conj of H_hat by σ^{−γ} simplifies to (ρ.M.conj (σ^γ).mat)^{α−1}. This uses σ^{−γ} · σ^γ = identity (on support) to cancel the outer σ^γ factors. -/ theorem H_hat_conj_sigma (hα : 1 < α) (ρ σ : MState d) : let γ := (1 - α) / (2 * α) (H_hat α ρ σ).conj (σ.M ^ (-γ)).mat = (ρ.M.conj (σ.M ^ γ).mat) ^ (α - 1) := by intro γ have hγ :...

Exact Lean statement

theorem f_alpha_at_optimizer (hα : 1 < α) (ρ σ : MState d) :
    f_alpha α (H_hat α ρ σ) ρ σ = Q̃_ α(ρ‖σ)

Formal artifact

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Full Lean sourceLean 4
theorem f_alpha_at_optimizer (hα : 1 < α) (ρ σ : MState d) :    f_alpha α (H_hat α ρ σ) ρ σ = Q̃_ α(ρ‖σ) := by  have h_inner : ⟪ρ.M, H_hat α ρ σ⟫_ = ((ρ.M.conj (σ.M ^ ((1 - α) / (2 * α))).mat) ^ α).trace := by    exact inner_rho_H_hat hα ρ σ  have h_conj : (H_hat α ρ σ).conj (σ.M ^ ((α - 1) / (2 * α))).mat = (ρ.M.conj (σ.M ^ ((1 - α) / (2 * α))).mat) ^- 1) := by    convert H_hat_conj_sigma ( hα := hα ) ( ρ := ρ ) ( σ := σ ) using 1    ring_nf!  unfold f_alpha sandwichedTraceFunctional  simp_all [ sub_div ]  rw [  HermitianMat.rpow_mul ] ; norm_num [ show α  0 by positivity, show α - 1  0 by linarith ];  · rw [ mul_div_cancel₀ _ ( by linarith ) ] ; ring;  · apply_rules [ HermitianMat.conj_nonneg ];    exact ρ.nonneg
Project
quantumInfo
License
MIT
Commit
56e83a9288a3
Source
QuantumInfo/Finite/Entropy/DPI.lean:453-465

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Conj Transpose isometry mul isometry le one

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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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Source project: quantumInfo

Person-level attribution pending.

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Project-declaredLean 4.28.0

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Plain-language statement

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Source project: quantumInfo

Person-level attribution pending.

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Project-declaredLean 4.28.0

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Plain-language statement

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Source project: quantumInfo

Person-level attribution pending.

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