Comparing Remnant Properties from Horizon Data and Asymptotic Data in Numerical Relativity

TL;DR

This paper compares local and asymptotic measurements of black hole remnants from numerical simulations, providing insights into their consistency and improving methods for analyzing black hole properties.

Contribution

It introduces a comparative analysis of horizon and asymptotic data for black hole remnants, enhancing accuracy in remnant property estimation and offering new evaluation techniques.

Findings

Asymptotic data can reliably reproduce local remnant properties.

Improved recoil velocity estimates for black hole mergers.

New methods for assessing numerical relativity simulation accuracy.

Abstract

We present a new study of remnant black hole properties from 13 binary black hole systems, numerically evolved using the Spectral Einstein Code. The mass, spin, and recoil velocity of each remnant were determined quasi-locally from apparent horizon data and asymptotically from Bondi data $(h, \psi_4, \psi_3, \psi_2, \psi_1)$ computed at future null infinity using SpECTRE's Cauchy characteristic evolution. We compare these independent measurements of the remnant properties in the bulk and on the boundary of the spacetime, giving insight into how well asymptotic data are able to reproduce local properties of the remnant black hole in numerical relativity. We also discuss the theoretical framework for connecting horizon quantities to asymptotic quantities and how it relates to our results. This study recommends a simple improvement to the recoil velocities reported in the Simulating eXtreme Spacetimes waveform catalog, provides an improvement to future surrogate remnant models, and offers new analysis techniques for evaluating the physical accuracy of numerical simulations.