CONSTRAINTS ON NONLUMINOUS MATTER FROM HIGHER ORDER PULSAR PERIOD DERIVATIVES

Pulsar timing can detect the discreteness of the mass distribution in the Galaxy. The jerk imposed on millisecond pulsars by their nearest neighbors, and on the Sun by its nearest neighbor, may be detectable presently or within a decade. The method can detect planets in the outer solar system out to distances of several thousand AU, with the sensitivity rapidly increasing with time.