Polarization of gravitational geodesic synchrotron radiation

Abstract

We calculate gravitational radiation as emitted by a test particle moving in a relativistic geodesic circular orbit in the Schwarzschild geometry. For this purpose we first give a compact version of the perturbation technique (using tensor spherical harmonics) for tensor radiation perturbing the Schwarzschild geometry. The polarization properties are analyzed with the help of gravitational Stokes parameters. The radiation is almost totally linearly polarized within the main beam, but the various polarization quantities depend much more strongly on the latitude angle of observation than they do for the analogous electromagnetic radiation at the same frequencies.