and
are both nonnegative definite Hermitian matrices and
is also nonnegative definite, then the singular values of A and B satisfy the inequalities
, where
denote the singular values of a matrix. A consequence of this property is that, in a nonsquare H^{infty} optimization problem, if
, then the singular values of
and
satisfy the inequality
where
is the number of columns of the matrix
.