Symmetric Feller semigroup
= Symmetric Feller semigroup
{title2=$\langle P_tf,g\rangle_{L^2(\mu)}=\langle f,P_tg\rangle_{L^2(\mu)}$}
A <Feller semigroup> symmetric in the space associated with an invariant measure has a self-adjoint contraction realization in $L^2(\mu)$. Its two-point kernel measure $\mu(dx)P_t(x,dy)$ is symmetric. This reversibility expresses its joint energy as an integral of products of increments.
// Target: analysis.bigb