In order to analyse gravitational wave events detected by the LIGO-Virgo interferometers accurate theoretical predictions are needed. Most of the gravitational wave models included in the Ligo Algorithm Library compute the waveform emitted by quasi-circular binary systems: using these models, one cannot capture a different phenomenology. The TEOBResumS model, based on the effective-one-body approach, is recently been modified to generate hyperbolic encounters and dynamical capture waveforms for binary black hole binaries (arXiv:2009.12857). These could be used to study whether the strange parameters extracted from the GW190521 event are indeed coming from an unusual parameters (high, misaligned spins) of a quasi-circular system or whether they are the result of using a quasi-circular model to interpret a different type of encounter.
A recording of Piero's talk can be found here.