Ra. Horn, NORM BOUNDS FOR HADAMARD-PRODUCTS AND AN ARITHMETIC - GEOMETRIC MEAN INEQUALITY FOR UNITARILY-INVARIANT NORMS, Linear algebra and its applications, 224, 1995, pp. 355-361
An arithmetic-geometric mean inequality for unitarily invariant norms
and matrices, 2\\AXB\\ less than or equal to \\AA*X + XBB*\\, is an i
mmediate consequence of a basic inequality for singular values of Hada
mard products.