A determinantal inequality for correlation matrices (Q5903711)

The author shows that for \(A=(a_{ij})\), a positive semidefinite matrix with \(a_{11}=a_{22}=...=a_{nn}=1\), and \(B=(| a_{ij}|\) 2), every eigenvalue \(\lambda\) of B satisfies \(\lambda\geq \det A\), by giving the case of equality for nonsingular A.