Explain the discrepancy in eccentricity inference for GW190521 across analyses and waveform models

Ascertain the origin of the discrepancy between previous analyses that suggested significant eccentricity for GW190521 and analyses using the multipolar aligned-spin eccentric model SEOBNRv4EHM (and TEOBResumS-DALI) that do not find evidence for eccentricity, identifying whether the difference is due to waveform-model assumptions (e.g., merger–ringdown treatment), data conditioning, parameterization, or other methodological factors.

Background

The authors find no evidence for eccentricity in GW190521 using SEOBNRv4EHM, consistent with other recent studies, whereas earlier works inferred eccentricity for this event. Since current eccentric waveform models assume quasi-circular merger–ringdown and GW190521 is merger–ringdown dominated, inference may be sensitive to modeling choices.

Resolving this discrepancy is critical to understanding GW190521’s astrophysical origin and to validating or improving eccentric waveform models for short, high-mass signals.