Dirac equation in Schwarzschild geometry

The Dirac equation is formulated in the standard Schwarzschild space-time by means of the spinorial formalism of Newman and Penrose. The solution is obtained by applying a separation method very similar to the one used by Chandrasekhar in the Kerr metric case. The separated time and angular equations come out to have known solutions, while the separated radial equations result in a form that allows an integration by series. In order to cover the range of variability of the radial coordinate, the solutions are expanded both about a regular singularity and a regular point