Comparing Extreme Mass Ratio Inspiral model Fidelity and Signal-to-Noise Ratio Estimates for LISA

Extreme mass ratio inspirals (EMRIs) are binary systems consisting of a stellar mass compact object and a massive black hole (MBH) that emit millihertz gravitational waves (GWs) for months to years. This makes them promising sources for future space-based millihertz GW observatories, such as the Laser Interferometer Space Antenna (LISA). LISA will rely on accurate simulations of EMRI gravitational waveforms to observe and characterize these systems. However, producing accurate EMRI waveforms is difficult, especially when considering eccentric orbits and MBHs with spin (known as Kerr black holes), often leading to the usage of kludge model approximations. Therefore, we wish to understand how well kludge models characterize EMRIs with rapidly rotating MBHs and their LISA signal-to-noise ratios (SNRs) in relation to more accurate, but computationally expensive, relativistic models. Within this preliminary investigation we make use of the augmented analytic kludge (AAK) model in the Fast EMRI Waveform (FEW) code and build our own relativistic model for EMRIs consisting of small bodies on eccentric, equatorial inspirals into rotating MBHs. We then compare each model’s ability to create accurate trajectories, waveforms, and SNRs for varying spins, eccentricities, mass ratios, and observational times.