On the gravitational lensing interpretation of three gravitational wave detections in the mass gap by LIGO and Virgo

Understand

We search for gravitational wave (GW) events from LIGO-Virgo's third run that may have been affected by gravitational lensing.

• Gravitational lensing delays the arrival of GWs, and alters their amplitude -- thus biasing the inferred progenitor masses.
• This would provide a physically well-understood interpretation of GW detections in the ''mass gap'' between neutron stars and black holes, as gravitationally lensed binary neutron star (BNS) mergers.
• We selected three GW detections in LIGO-Virgo's third run for which the probability of at least one of the constituent compact objects being in the mass gap was reported as high with low latency -- i.e.