Collisions of unequal mass black holes and the point particle limit

Ulrich Sperhake, Vitor Cardoso, Christian D. Ott, Erik Schnetter, Helvi Witek

Research output: Contribution to journalArticlepeer-review


Numerical relativity has seen incredible progress in the last years, and is being applied with success to a variety of physical phenomena, from gravitational wave research and relativistic astrophysics to cosmology and high-energy physics. Here we probe the limits of current numerical setups, by studying collisions of unequal mass, nonrotating black holes of mass ratios up to 1 100 and making contact with a classical calculation in general relativity: the infall of a pointlike particle into a massive black hole. Our results agree well with the predictions coming from linearized calculations of the infall of pointlike particles into nonrotating black holes. In particular, in the limit that one hole is much smaller than the other, and the infall starts from an infinite initial separation, we recover the point-particle limit. Thus, numerical relativity is able to bridge the gap between fully nonlinear dynamics and linearized approximations, which may have important applications. Finally, we also comment on the "spurious" radiation content in the initial data and the linearized predictions.

Original languageEnglish (US)
Article number084038
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number8
StatePublished - Oct 18 2011
Externally publishedYes

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)


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