Numerical range
= Numerical range
{wiki}
The numerical range of an operator $A$ is
$$
N(A)=\{\langle\psi|A|\psi\rangle:\|\psi\|=1\}.
$$
= Numerical range
{wiki}
The numerical range of an operator $A$ is
$$
N(A)=\{\langle\psi|A|\psi\rangle:\|\psi\|=1\}.
$$