Stieltjes matrix resolvent (source code)

= Stieltjes matrix resolvent
{c}
{title2=$G_X(z)=(X-zI)^{-1}$}

For a <Hermitian matrix> $X$ and nonreal $z$, this is the negative of the usual <resolvent of an operator> convention $(zI-X)^{-1}$. Its normalized trace is the <Stieltjes transform of a measure> of the <empirical spectral measure> with kernel $(x-z)^{-1}$. Naming the convention prevents sign errors in self-consistency identities.