A note on gravitational wave extraction from binary simulations

TL;DR

This paper improves gravitational wave extraction from binary black hole simulations by deriving an enhanced extrapolation formula using the Teukolsky equation for Kerr backgrounds, accounting for mass and spin.

Contribution

It introduces an improved extrapolation method based on the Teukolsky formalism, extending previous flat spacetime approaches to Kerr backgrounds with error estimation.

Findings

Enhanced accuracy in gravitational wave extraction.

Error estimates for the extrapolation formula.

Applicability to Kerr background simulations.

Abstract

In previous works, we developed a perturbative extrapolation formula to obtain gravitational waves at infinity from binary black hole simulations, based on the Regge-Wheeler-Zerilli formalism. In practice, this formula was basically derived in a background flat spacetime. We derive here an estimation of errors and an improved extrapolation formula by using the Teukolsky perturbative equation for a background Kerr spacetime. The improved formula requires knowledge about a mass and spin of the background spacetime.