Strong internal gravity is incorporated in a divergent-free post-Newtonian approximation scheme by introducing a body-zone limit. When incorporated into the notion of sequences of solutions, this provides the first rigorous point-particle limit in general relativity. The scheme is applied to construct an asymptotic approximation to a binary system composed of two rotating neutron stars. The lowest-order calculation is carried out in the near and far zones, giving Newtons equations of motion and the far-zone quadrupole formula. The quadrupole moment of the system is expressed in terms of a mass integral over each compact star. The same mass appears in Newtons equations of motion. The mass is indeed the Arnowitt-Deser-Misner mass the compact star would have if it were isolated. Thus the equivalence principle for strong gravity is confirmed, even for gravitational radiation: gravitational potential energy radiates the same amount of gravitational waves as any other form of energy does.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)