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Abstract

We study a compensated homogeneous permanent derivative on centered Hermitian positive semidefinite matrices of order six. An exact Hermitian sum-of-squares certificate proves F_4(K)>8000(tr K)^4 for every nonzero centered complex positive semidefinite rank-one matrix, with no conjugate-disjointness assumption. We also prove a quantitative phase-boundary reduction: positivity of the actual derivative propagates from a saturated phase endpoint to its entire feasible ray, with a strictly positive reserve. Combining the two results gives F_4(K)>5040(tr K)^4 whenever rank(Re K)≤2, including unequal real spectra and singular boundaries. A complementary common-state tensor dual certifies every feasible phase over an explicit noncirculant real base and a closed neighborhood outside the previously established spectral domain. The proofs use an opposite bound for the pure quartic phase term, exact rational certificates, and complete original-permanent coefficient reconstruction.