Operator convex function
= Operator convex function
{wiki}
A real function $f$ on an interval $I$ is operator convex when
$$
f(\lambda A+(1-\lambda)B)
\leq\lambda f(A)+(1-\lambda)f(B)
$$
in the <Loewner order> for all <Hermitian operators> $A,B$ with spectra in $I$ and every $0\leq\lambda\leq1$.
= Operator convex
{synonym}