Effective-one-body multipolar waveforms for eccentric binary black holes with non-precessing spins

Abstract

We construct an inspiral-merger-ringdown eccentric gravitational-wave (GW) model for binary black holes with non-precessing spins within the effective-one-body formalism. This waveform model, SEOBNRv4EHM, extends the accurate quasi-circular SEOBNRv4HM model to eccentric binaries by including recently computed eccentric corrections up to 2PN order in the gravitational waveform modes, notably the (l, |m|) = (2, 2), (2, 1), (3, 3), (4, 4), (5, 5) multipoles. The waveform model reproduces the zero eccentricity limit with an accuracy comparable to the underlying quasi-circular model, with the unfaithfulness of 1% against quasicircular numerical-relativity (NR) simulations. When compared against 28 public eccentric NR simulations from the Simulating eXtreme Spacetimes catalog with initial orbital eccentricities up to e 0.3 and dimensionless spin magnitudes up to +0.7, the model provides unfaithfulness < 1%, showing that both the (2, |2|)-modes and the higher-order modes are reliably described without calibration to NR datasets in the eccentric sector. The waveform model SEOBNRv4EHM is able to qualitatively reproduce the phenomenology of dynamical captures, and can be extended to include spin-precession effects. It can be employed for upcoming observing runs with the LIGO-Virgo-KAGRA detectors and used to re-analyze existing GW catalogs to infer the eccentricity parameters for binaries with e 0.3 (at 20 Hz or lower) and spins up to 0.9 − 0.95. The latter is a promising region of the parameter space where some astrophysical formation scenarios of binaries predict mild eccentricity in the ground-based detectors' bandwidth. Assessing the accuracy and robustness of the eccentric waveform model SEOBNRv4EHM for larger eccentricities and spins will require comparisons with, and, likely, calibration to eccentric NR waveforms in a larger region of the parameter space.

Assessment of Effective-One-Body Radiation Reactions for Generic Planar Orbits

“…In its latest avatar [13], the TEOBResumS model for generic, but pla-nar, orbital motion displays: (i) an excellent agreement (EOB/NR unfaithfulness mostly around 0.1% except a single outlier ∼ 1%) with the 28 Numerical Relativity (NR) public simulations of eccentric inspirals of the Simulating eXtreme Spacetimes (SXS) catalog and (ii) a high consistency (maximum disagreement ∼ 4% for the most relativistic configurations) with the only available NR calculation of the scattering angle [33]. Parallel work has extended the quasicircular SEOBNRv4HM model to to eccentric inspirals [15,16,34,35] and presented qualitative results for EOB waveforms for hyperbolic encounters [20]. In particular SEOBNRv4EHM [20] showed a EOB/NR unfaithfulness mostly around 0.1% for all the 28 numerical relativity datasets available from the SXS collaboration.…”

“…Despite the small EOB/NR unfaithfulness found in Ref. [20] for (mild) eccentricities, no dedicated study of the QC radiation reaction in eccentric inspirals was undertaken. Reference [19] computed noncircular corrections up to 2PN order in the waveform that, once incorporated into the QC waveform, constitute another possible prescription for the EOB radiation reaction.…”

“…Parallel work has extended the quasicircular SEOBNRv4HM model to to eccentric inspirals [15,16,34,35] and presented qualitative results for EOB waveforms for hyperbolic encounters [20]. In particular SEOBNRv4EHM [20] showed a EOB/NR unfaithfulness mostly around 0.1% for all the 28 numerical relativity datasets available from the SXS collaboration. The EOB radiation reaction consists of an azimuthal component F ϕ and a radial component F r .…”

“…Motivated by recent observational hints for eccentric and hyperbolic binary black hole mergers in some LIGO-Virgo events [1][2][3] and by future prospect of detecting binary sources on generic orbits with LISA [4][5][6], the analytical relativity community has intensified the efforts in building up accurate gravitational-wave (GW) models for noncircularized coalescing compact binaries [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Among the possible approaches, the effective-one-body (EOB) framework [22][23][24][25][26] offers a theoretically complete method for a unified description of different classes of astrophysical binaries, from the comparable masses to the intermediate and extreme mass-ratio regimes, and for incorporating the fast motion and ringdown dynamics.…”

“…[21] at 2PN accuracy. By contrast, a different approach was taken in the SEOBNRv4EHM model [20], that uses the standard quasi-circular (QC) azimuthal radiation reaction force F ϕ inherited from the quasi-circular SEOBNRv4HM model [44,45], without taking care of explicit nonradial contributions to the loss of angular momentum. Despite the small EOB/NR unfaithfulness found in Ref.…”