Comparison between numerical relativity and a new class of post-Newtonian gravitational-wave phase evolutions: the non-spinning equal-mass case

TL;DR

This paper compares the phase evolution of equal-mass nonspinning black-hole binaries from numerical relativity with three post-Newtonian approximants, revealing differences and convergence behaviors among them.

Contribution

It introduces and evaluates the TaylorEt approximant against established methods T1 and T4 in modeling gravitational-wave phase evolution.

Findings

TaylorEt shows larger initial disagreement but improves with higher PN order.

Discrepancy between NR and PN decreases as PN order increases.

TaylorEt's phase disagreement decreases monotonically with PN order.

Abstract

We compare the phase evolution of equal-mass nonspinning black-hole binaries from numerical relativity (NR) simulations with post-Newtonian (PN) results obtained from three PN approximants: the TaylorT1 and T4 approximants, for which NR-PN comparisons have already been performed in the literature, and the recently proposed approximant TaylorEt. The accumulated phase disagreement between NR and PN results over the frequency range $M\omega = 0.0455$ to $M\omega = 0.1$ is greater for TaylorEt than either T1 or T4, but has the attractive property of decreasing monotonically as the PN order is increased.