Reducing eccentricity in black-hole binary evolutions with initial parameters from post-Newtonian inspiral

TL;DR

This paper presents a simple method to significantly reduce eccentricity in black-hole binary simulations by using post-Newtonian inspiral data to set initial parameters, improving the accuracy of numerical relativity evolutions.

Contribution

The authors introduce a straightforward approach to minimize eccentricity in black-hole binary initial data by integrating post-Newtonian equations, enhancing simulation precision.

Findings

Eccentricity reduced by at least a factor of five

Achieved eccentricity below 0.002 for specific initial conditions

Method applicable to non-spinning equal-mass inspirals

Abstract

Standard choices of quasi-circular orbit parameters for black-hole binary evolutions result in eccentric inspiral. We introduce a conceptually simple method, which is to integrate the post-Newtonian equations of motion through hundreds of orbits, and read off the values of the momenta at the separation at which we wish to start a fully general relativistic numerical evolution. For the particular case of non-spinning equal-mass inspiral with an initial coordinate separation of $D = 11M$ we show that this approach reduces the eccentricity by at least a factor of five to $e < 0.002$ as compared to using standard quasi-circular initial parameters.