Plunge-Merger-Ringdown Tests of General Relativity with GW250114

TL;DR

This paper uses the GW250114 gravitational wave event to perform the most precise tests of general relativity during the plunge-merger-ringdown phase, constraining deviations with improved accuracy over previous analyses.

Contribution

It introduces a parametrized waveform model within the effective-one-body formalism to constrain deviations from general relativity during the plunge-merger-ringdown stage of spin-precessing binaries.

Findings

Deviations from peak amplitude constrained to about 10%.

Deviations from instantaneous frequency constrained to about 4%.

First-time constraints on the frequency of the (4,4) mode and peak time of the waveform.

Abstract

The binary black hole signal GW250114, the clearest gravitational wave detected to date, offers a unique opportunity to test general relativity in the relativistic strong-gravity regime. How well does GW250114 agree with Einstein's predictions in the plunge-merger-ringdown stage? To address this point, we constrain deviations from general relativity across the plunge-merger-ringdown stage of spin-precessing binaries with a parametrized waveform model within the effective-one-body formalism. We find that deviations from the peak gravitational-wave amplitude and instantaneous frequency of the $(\ell, |m|)=(2,2)$ mode are constrained to about $10\%$ and $4\%$, respectively, at $90\%$ credible level. These constraints are, respectively, two and four times more stringent than those obtained by analyzing GW150914. We also constrain, for the first time, the instantaneous frequency of the $(\ell, |m|)=(4,4)$ mode at merger to about $6\%$, and the time at which the gravitational-wave amplitude peaks to about $5~\mathrm{ms}$. These results are the most precise tests of general relativity in the nonlinear regime to date, and can be employed to constrain extensions of Einsten's theory.