The explicit right-polar blocks
Abstract
Exact radical rotations for the active reverse source matrix.
Set s = sqrt(11), t = sqrt(10), D(l) = sqrt((l s + 3t)^2 + (s-t)^2), c(l) = (l s + 3t)/D(l), and k(l) = (s-t)/D(l). The two coupled blocks use l = 4 and l = 2. The remaining block is t times the matrix with diagonal 3 and off-diagonal -1. The active source matrix is Y diag(s,t,t,s,t,t)/62.
Theorem 1.1 (The fixed radical unitary).
Lean statement: D5/S3/Quantum/Recovery/BurriReversePolar.actual_unitary
Proof. Machine-checked in Lean as D5/S3/Quantum/Recovery/BurriReversePolar.actual_unitary (✓ std3). ∎
Source. Repository-derived.
Commentary.
Both exact radical parameter pairs satisfy the unit-circle equation. The active matrix U therefore satisfies both complex unitary identities, and both sine parameters are strictly positive.
Theorem 1.2 (A positive source polar product).
Lean statement: D5/S3/Quantum/Recovery/BurriReversePolar.actual_polar_positive
Proof. Machine-checked in Lean as D5/S3/Quantum/Recovery/BurriReversePolar.actual_polar_positive (✓ std3). ∎
Source. Repository-derived.
Commentary.
The literal active product M U is positive semidefinite. Each coupled block is symmetric with positive first diagonal entry and determinant (3l-1)s t. Unnormalized Hadamard columns reconstruct the complete six-dimensional product as a sum of positive congruences.
Theorem 1.3 (A literal nonnegative SVD).
Lean statement: D5/S3/Quantum/Recovery/BurriReversePolar.active_svd
Proof. Machine-checked in Lean as D5/S3/Quantum/Recovery/BurriReversePolar.active_svd (✓ std3). ∎
Source. Repository-derived.
Commentary.
The Hermitian spectral decomposition of the positive product supplies two unitary factors and nonnegative singular values. Their source-ordered adjoints multiply to the explicit active rotation. This statement concerns the active block; its full source padding is a further identification.
Theorem 1.4 (The fixed positive polynomial gap).
Lean statement: D5/S3/Quantum/Recovery/BurriReversePolar.actual_polynomial_gap
Proof. Machine-checked in Lean as D5/S3/Quantum/Recovery/BurriReversePolar.actual_polynomial_gap (✓ std3). ∎
Source. Repository-derived.
Commentary.
The exact radical parameters discharge every premise of the sum-of-squares positivity statement. This is an algebraic certificate; an actual decoder fidelity comparison additionally requires the canonical-purification and ordinary Petz identities.
References
- Truth anchor:
D5/S3/Quantum/Recovery/BurriReversePolar.active_svd - Truth anchor:
D5/S3/Quantum/Recovery/BurriReversePolar.actual_polar_positive - Truth anchor:
D5/S3/Quantum/Recovery/BurriReversePolar.actual_polynomial_gap - Truth anchor:
D5/S3/Quantum/Recovery/BurriReversePolar.actual_unitary - Dependency: D5/S3/Quantum/Matrix/SpectralPower
- Dependency: D5/S3/Quantum/Recovery/BurriReverseDecoder