224a
Let
The change of variables
The full proof is given in Reed and Simon VII.3.
We showed that a large class of perturbations preserves selfadjointness, and used this to show that the Schrodinger operator with certain potentials (Coulomb and Yukawa) are selfadjoint. We sketched a proof that these perturbations retain some important features of the Laplacian, namely that the spectrum is bounded below and that the negative spectrum is pure point.
Details are given in Dimock 4.1-4.4.