Waveform uncertainty quantification and interpretation for gravitational-wave astronomy*

I demonstrate how to quantify the frequency-domain amplitude and phase accuracy of waveform models in a form that could be marginalized over in gravitational-wave inference using techniques similar to those currently applied for quantifying calibration uncertainty. For concreteness, waveform uncertainties affecting neutron-star inspiral measurements are considered, and post-hoc error estimates from a variety of waveform models are made by comparing time-domain and frequency-domain analytic models with multiple-resolution numerical simulations. These waveform uncertainty estimates can be compared calibration envelopes, and both calibration and waveform uncertainties can be compared to signal-specific statistical fluctuations in gravitational-wave observatories to suggest frequency-dependent modeling requirements. Finally, the distribution of waveform error for GW170817 over the parameters of the low-spin posterior is computed from tidal models and compared the constraints by Edelman et. al. on amplitude and phase differences from GWTC-1 observations. In general, recovered waveform differences can be interpreted in in terms of unmodeled astrophysical energy transfer within or from the source system.