# Reducing orbital eccentricity in binary black hole simulations

Document #:
LIGO-P070063-x0
Document type:
P - Publications
Abstract:
Binary black hole simulations starting from quasi-circular (i.e., zero radial velocity) initial data have orbits with small but nonzero orbital eccentricities. In this paper, the quasi-equilibrium initial-data method is extended to allow nonzero radial velocities to be specified in binary black hole initial data. New low-eccentricity initial data are obtained by adjusting the orbital frequency and radial velocities to minimize the orbital eccentricity, and the resulting (~5 orbit) evolutions are compared with those of quasi-circular initial data. Evolutions of the quasi-circular data clearly show eccentric orbits, with eccentricity that decays over time. The precise decay rate depends on the definition of eccentricity; if defined in terms of variations in the orbital frequency, the decay rate agrees well with the prediction of Peters (1964 Phys. Rev. 136 1224–32). The gravitational waveforms, which contain ~8 cycles in the dominant l = m = 2 mode, are largely unaffected by the eccentricity of the quasi-circular initial data. The overlap between the dominant mode in the quasi-circular evolution and the same mode in the low-eccentricity evolution is about 0.99.
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Rev P070063-00-Z:
- Full document number: LIGO-P070063-00-Z
- Author(s): Duncan Brown; Lawrence E. Kidder; Lee Lindblom; Geoffrey Lovelace; Harald P. Pfeiffer; Mark A. Scheel
- Document date: 2007-04-25