Ballistic orbits in Schwarzschild space-time and gravitational waves   from EMR binary mergers
  We describe a special class of ballistic geodesics in Schwarzschild space-time, extending to the horizon in the infinite past and future of observer time, which are characterized by the property that they are in 1-1 correspondence, and completely degenerate in energy and angular momentum, with stable circular orbits. We derive analytic expressions for the source terms in the Regge-Wheeler and Zerilli-Moncrief equations for a point-particle moving on such a ballistic orbit, and compute the gravitational waves emitted during the infall in an Extreme Mass Ratio black-hole binary coalescence. In this way a geodesic description for the plunge phase of compact binaries is obtained. 
G. d'Ambrosi, J.W. van Holten
gr-qc astro-ph.SR