Dirichlet forms for singular diffusion in higher dimensions

We describe singular diffusion in bounded subsets $\Omega$ of $\mathbb{R}^n$ by form methods and characterize the associated operator. We also prove positivity and contractivity of the corresponding semigroup. This results in a description of a stochastic process moving according to classical diffusion in one part of $\Omega$, where jumps are allowed through the rest of $\Omega$.