Maximum permanent and Hermitian matrices
The authors prove that a result of \textit{J. H. Drew} and \textit{C. R. Johnson} [Linear Multilinear Algebra 25, No. 3, 243-251 (1989; Zbl 0681.15004)] generalizes from real symmetric positive semidefinite \(3 \times 3\) matrices to Hermitian positive semidefinite \(3 \times 3\) matrices. This result gives the maximum permanent of matrices conjugate by unitary matrices to a fixed diagonal matrix (i.e. specified eigenvalues), and gives the form of the maximizing matrix.
Hermitian positive semidefinite matrices
scientific article; zbMATH DE number 871113