Inspiral-merger-ringdown waveforms with gravitational self-force results within the effective-one-body formalism

TL;DR

This paper introduces a new gravitational waveform model, SEOBNR-GSF, that incorporates gravitational self-force results into the effective-one-body framework, improving accuracy for a wide range of mass ratios in black hole mergers.

Contribution

First complete IMR waveform model built primarily from GSF results, integrating GSF-informed Hamiltonian into the EOB formalism.

Findings

Outperforms 2GSF inspiral waveforms in intermediate-to-comparable mass ratios.

Significantly improves model fidelity over PN-informed variants.

Achieves median mismatch comparable to state-of-the-art models against numerical relativity data.

Abstract

Gravitational self-force (GSF) theory is a strong-gravity perturbative approach to the relativistic two-body problem, primarily developed to model extreme-mass-ratio inspirals, where one compact object is significantly more massive than the companion. However, recent advancements in GSF calculations, particularly involving second-order self-force (2GSF) results, indicated a much broader applicability across a wider range of mass ratios. These developments have motivated efforts to incorporate GSF results into the effective-one-body (EOB) framework, where they have already been successfully integrated into the state-of-the-art waveform model, SEOBNRv5, employed in recent LIGO-Virgo-KAGRA (LVK) observing runs. In this work, we present SEOBNR-GSF, a nonspinning inspiral-merger-ringdown (IMR) EOB waveform model that introduces a GSF-informed EOB Hamiltonian as its central innovation. This marks the first complete IMR waveform model constructed primarily from GSF results. We show that our model outperforms inspiral waveforms from full 2GSF calculations in the intermediate-to-comparable mass regime. Furthermore, by comparing with a post-Newtonian-informed variant, SEOBNR-GSF-PN, we demonstrate that the inclusion of numerical GSF information in the Hamiltonian leads to significant improvements in model fidelity. Finally, we benchmark our model against high-accuracy, nonspinning numerical-relativity simulations from the Simulating eXtreme Spacetimes (SXS) catalogue and find that its median mismatch is comparable to that of SEOBNRv5, suggesting that this approach holds promise for further enhancing future EOB waveform models.