title: High-energy collision of two black holes.
abstract: We study the head-on collision of two highly boosted equal mass, nonrotating black holes. We determine the waveforms, radiated energies, and mode excitation in the center of mass frame for a variety of boosts. For the first time we are able to compare analytic calculations, black-hole perturbation theory, and strong field, nonlinear numerical calculations for this problem. Extrapolation of our results, which include velocities of up to 0.94c, indicate that in the ultrarelativistic regime about 14+/-3% of the energy is converted into gravitational waves. This gives rise to a luminosity of order 10_(-2)c_(5)/G, the largest known so far in a black-hole merger.
authors.affiliation: Theoretisch Physikalisches Institut, Friedrich Schiller Universität, 07743 Jena, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Sperhake
authors.forename: Vitor
authors.initials: V
authors.lastname: Cardoso
authors.forename: Frans
authors.initials: F
authors.lastname: Pretorius
authors.forename: Emanuele
authors.initials: E
authors.lastname: Berti
authors.forename: José A
authors.initials: JA
authors.lastname: González