Strong-field scattering of two spinning black holes: Numerics versus Analytics

TL;DR

This paper presents new numerical relativity calculations of black hole scattering angles involving spinning black holes, compares them with advanced analytical models, and highlights areas for model improvement.

Contribution

It introduces detailed numerical calculations for spinning black hole scattering and compares these with a novel effective one body analytical model incorporating high-order post-Newtonian data.

Findings

Numerical results show discrepancies with current analytical models for highly spinning configurations.

The analytical model requires further refinement in the spin sector to match numerical data.

The study advances understanding of spinning black hole interactions in strong gravity regimes.

Abstract

We present new Numerical Relativity calculations of the scattering angle $\chi$ between two, equal-mass, black holes on hyperbolic-like orbits. We build upon previous work considering, for the first time, spinning black holes, with equal spins either aligned or antialigned with the orbital angular momentum. We detail the numerical techniques used in the computation of $\chi$. Special care is taken in estimating error uncertainties on the quantities computed. The numerical values are compared with analytical predictions obtained using a new, state-of-the-art, effective one body model valid on generic orbits that incorporates post-Newtonian analytic information up to 5PN in the nonspinning, conservative sector and that has been additionally informed by Numerical Relativity simulations of quasi-circular coalescing black hole binaries. Our results indicate that the spin sector of the analytic model should be improved further in order to achieve satisfactory consistency with the most relativistic spinning configurations.