Tjonnie Li (The Chinese University of Hong Kong)
Gravitational Lensing of Gravitational Waves
Gravitational lensing phenomena are widespread in electromagnetic astrophysics, and in principle may also be uncovered with gravitational waves. I examine gravitational wave events in the limit of geometric optics, where one expects to see multiple signals from the same event with different arrival times and amplitudes, and wave optics, where one expects to see effects such as interference and diffraction.
Recent studies are showing that second generation gravitational-wave detectors may observe more than one lensed event. I present the results from a search for signatures of gravitational lensing in the binary black hole events detected by Advanced LIGO and Virgo during their first two observational runs. In particular, we look for three effects: 1) evidence of lensing magnification in the individual signals due to galaxy lenses, 2) evidence of multiple images due to strong lensing by galaxies, 3) evidence of wave optics effects due to point-mass lenses. We find no compelling evidence of any of these signatures in the observed gravitational wave signals. Finally, I will also look ahead to the microlensing effects due to substructure on top of strong lensing by (clusters of) galaxies. [link]
Place: KIAA-PKU Auditorium
Time: Thursday, April 4, 2019 - 4:00pm to 5:00pm