Positive energy in general relativity
We report on progress towards finding a local expression for radiation reaction for a particle orbiting a Kerr black hole. The Dirac-Gal'tsov approach is described. For the case of a scalar particle in a circular orbit of a Schwarzschild black hole, an explicit calculation is done via this method and shown to be in agreement with overall energy conservation. A possible approach to the case of more general orbits is also discussed.