Eccentric surrogate waveform model for non-spinning binary black-hole systems

Recently, there has been an increased interest in modeling gravitational waves (GWs) from eccentric binary black hole (BBH) systems, as certain formation channels predict a fraction of detectable binaries could enter the sensitivity band with a measurable eccentricity in future LIGO observing runs (O4 and beyond). Numerical relativity (NR) simulations accurately give the evolution of a binary black-hole (BBH) system and the emitted GW signal. But unfortunately, NR simulations are computationally expensive and cannot be used directly for generating template waveforms for parameter estimation. Surrogate modeling is a data-driven approach that is both fast and accurate in reproducing NR simulations. We present the first 3-dimensional surrogate model for waveforms from eccentric BBH systems that does not require the binary to circularize before merger, with mass ratios from 1 to 4 eccentricity less than 0.4 as measured at a reference time about 20 orbits before merger. Trained directly against 109 NR simulations, these models are shown to reproduce the simulations nearly as accurately as the simulations themselves.