Gravitational Radiation from a Mass Projected into a Schwarzschild Black Hole

Gravitational radiation emitted by a particle projected with nonzero kinetic energy from infinite distance into a Schwarzschild black hole is examined. Direct comparison between a semirelativistic approach and the fully relativistic approach in the Regge-Wheeler-Zerilli formalism gives an insight into the nature of the results. Detailed spectral distributions are given. Contrary to the case in which the particle falls in with zero kinetic energy, the spectrum does not vanish any more at low frequencies and a considerably larger amount of radiation is emitted.