GRAVITATIONAL WAVES FROM COALESCING BINARY SOURCES

Coalescing binary systems (e.g. pulsars, neutron stars and black holes) are currently considered to be the most likely sources of gravitational radiation, yet to be detected on or near Earth, where the local gravitational field is negligible and the Poincaré symmetry rules. On the other hand, the general theory of gravitational waves emitted by axially symmetric rotating sources predicts the existence of a nonvanishing news function. The existence of such function implies that, for a distant observer, the asymptotic group of isometries, the BMS group, has a translational symmetry that depends on the orbit periodicity of the source, thus breaking the isotropy of the Poincaré translations. These results suggest that the asymptotic BMS-covariant wave equation should be applied to obtain a proper theoretical basis for the gravitational waves observations from those binary sources.