Collisions of unequal mass black holes and the point particle limit
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.
Additional Information© 2011 American Physical Society. Received 31 May 2011; published 18 October 2011. We thank E. Mitsou for sharing data from his earlier work , which helped assess the accuracy of our own PP wave forms and fluxes. U. S. acknowledges support from the Ramón y Cajal Programme of the Ministry of Education and Science of Spain, FP-7-PEOPLE-2011-CIG Grant CBHEO, No. 293412, NSF Grant Nos. PHY-0601459, PHY-0652995 and the Sherman Fairchild Foundation to Caltech. H.W. is funded by FCT through Grant No. SFRH/BD/46061/2008. This work was supported by the DyBHo-256667 ERC Starting Grant and by FCT—Portugal through Project Nos. PTDC/FIS/098025/2008, PTDC/FIS/098032/2008 CTE-AST/098034/2008 and CERN/FP/116341/2010, by the NSF under Grant Nos. PHY-090003, PHY-100033, and OCI-0905046, Grant Nos. ICTS-CESGA-175 and ICTS-CESGA-200, AECT-2011-02-0006 and AECT-2011-02-0015. C.D.O. acknowledges support from the NSF under Grant No. AST-0855535. E. S. acknowledges support from the NSF under Grant No. 0721915 (Alpaca) and NSF Grant No. 0904015 (CIGR). We acknowledge the support of the National Institute for Computational Sciences (NICS) of the University of Tennessee, the San Diego Supercomputing Center (SDSC), the Centro de Supercomputación de Galicia (CESGA) and the Barcelona Supersomputing Center (BSC). Computations were performed on the TeraGrid clusters NICS Kraken, SDSC Trestles, on CESGA's Finis Terrae cluster, on the University of Zaragoza's BIFI Caesaraugusta, on the Milipeia cluster in Coimbra, BSC's Mare Nostrum and LRZ Munich.
Published - Sperhake2011p16484Phys_Rev_D.pdf