The One-Center Point Interaction in Three Dimensions

Abstract

In this section we develop a precise formulation for the point interaction (also called δ, or zero-range, or contact interaction or Fermi pseudopotential in the physics literature) centered at a fixed point y in three dimensions. Although our methods concentrate mainly on the concept of self-adjoint operator extensions, an alternative approach based on local Dirichlet forms is sketched at the end of the section.