High Energy Theory and Center of Gravity Seminar: Aldo Gamboa

Title: Accurate waveform models of eccentric binary black holes

Abstract: The detection and characterization of gravitational waves (GWs) rely on the availability of accurate waveform templates that describe a variety of astrophysical sources, such as the stellar-mass black hole (BH) binaries observed by the LIGO-Virgo-KAGRA detectors. Key physical parameters (including the component masses, spins, and orbital eccentricity) allow us to distinguish between different formation channels of BH binaries. In particular, orbital eccentricity is regarded as a smoking gun for binaries formed through dynamical interactions in dense stellar environments. Yet, most GW analyses so far have been conducted under zero-eccentricity assumptions. Neglecting eccentricity, however, can introduce significant biases in parameter estimation and in tests of General Relativity. This underscores the need for accurate waveform models for coalescing binaries on eccentric orbits. An important semi-analytical framework in this context is the effective-one-body (EOB) formalism which combines various analytical approximation methods with information obtained from numerical-relativity simulations. This framework has proven reliable in modeling the inspiral-merger-ringdown waveform of binaries on generic orbits. In this seminar, I will first motivate the need for accurate, robust, and efficient waveform models for eccentric binaries. Then, I will give an overview of the state-of-the-art waveform models that are being employed for eccentric GW analyses, focusing in particular on the SEOBNR family of models and discuss its latest applications in GW science. Finally, I will outline ongoing efforts to improve the accuracy of EOB models for highly eccentric binaries and to extend their validity to generic (eccentric, spin-precessing) systems, which is crucial for achieving a more complete understanding of binary formation channels.