Superposition Principle in Relativistic Gravity

We present a simple model for relativistic gravity. The model represents a gravitational field by a metric on a Minkowski space background. We introduce a new Lorentz-covariant metric for a single-source gravitation field, which is determined by the retarded position and the velocity of the source. This metric passes the $GR$ tests and properly describes the strong gravitational field. Using this metric, we define the metric of a field generated by several moving sources. The explicit true acceleration of an object moving in this field is derived from the ``first-order" (in the masses of the sources) acceleration, which is linear in the sources. The field splits into near and far fields. We compare the far gravitational field of a binary star with electromagnetic quadruple radiation and present an algorithm for computing accelerations in such a field. These results may lead to a new understanding of gravitational waves and the structure and dynamics of galaxies