Abstract
Let be bounded linear operators on a complex separable Hilbert space and let be positive real numbers such that
and . Among other results, it is shown that (a) If f is a non-negative function on such that and is convex, then for every unitarily invariant norm,
for .
(b) If f is a non-negative function on such that is concave, then for every unitarily invariant norm,
for . Here
Notes
No potential conflict of interest was reported by the authors.