Scalar spectral measure
= Scalar spectral measure
{title2=$\mu_{v,w}$}
For a <projection-valued measure> $E$ and vectors $v,w$, the scalar spectral measure is the complex measure $\mu_{v,w}(B)=\langle E(B)v,w\rangle$. The positive measure $\mu_v=\mu_{v,v}$ has total mass $\|v\|^2$.