Loewner order
= Loewner order
{wiki=Loewner_order}
Loewner order, named after the mathematician Charles Loewner, is a way to compare positive definite matrices. In particular, for two symmetric matrices \\( A \\) and \\( B \\), we say that \\( A \\) is less than or equal to \\( B \\) in the Loewner order, denoted \\( A \\preceq B \\), if the matrix \\( B - A \\) is positive semidefinite.