Identifying strongly lensed gravitational wave signals from binary black hole mergers

Understand

Based on the rate of gravitational-wave (GW) detections by Advanced LIGO and Virgo, we expect these detectors to observe hundreds of binary black hole mergers as they achieve their design sensitivities (within a few years).

• A small fraction of them can undergo strong gravitational lensing by intervening galaxies, resulting in multiple images of the same signal.
• To a very good approximation, the lensing magnifies/de-magnifies these GW signals without affecting their frequency profiles.
• We develop a Bayesian inference technique to identify pairs of strongly lensed images among hundreds of binary black hole events and demonstrate its performance using simulated GW observations.