Second post-Newtonian radiative evolution of the relative orientations of angular momenta in spinning compact binaries - art. no. 024007

The radiative evolution of the relative orientations of the spin and orbita l angular momentum vectors S-1, S-2 and L, characterizing a binary system o n an eccentric orbit is studied up to the second post-Newtonian order. As a n intermediate result, all Burke-Thorne type instantaneous radiative change s in the spins are shown to average out over a radial period. It is proved that spin-orbit and spin-spin terms contribute to the radiative angular evo lution equations, while Newtonian, first and second post-Newtonian terms to gether with the leading order tail terms do not. In complement to the spin- orbit contribution, given earlier, the spin-spin contribution is computed a nd split into two-body and self-interaction parts. The latter provide the s econd post-Newtonian order corrections to the 3/2 order Lense-Thirring desc ription.