Curving Spacetime Curvature: Hunting for Gravitational Lensing of Gravitational Waves

Recent detections of gravitational waves herald a new era where
invisible black holes and neutron stars can be discovered throughout
the Universe. Similar to light, gravitational waves can be distorted by
massive objects between the observer and the source, i.e.
gravitational lensing. Neglecting the effects of lensing can lead to
missing gravitational-wave events or a biased measurement the
source. In particular, in the geometrical-optics limit, lensing may give
rise to repeated signals from the same source that are
(de-)magnified. In the wave-optics limit, effects like diffraction,
interference and dispersion may deform the signal morphology to an
extent that they no longer match with our standard description.
However, if these challenges are successfully addressed then, the
effects of gravitational lensing have the ability to uncover a
population of objects or structures that are intrinsically faint and can
otherwise not be found. Moreover, they provide us with a way to
study the large-scale structure of the Universe or even probe
fundamental aspects of gravity.
I propose to systematically study the effects of lensing on the
detection and interpretation of gravitational-wave signals. Moreover, I
will extend existing LIGO infrastructure to account for the effects of
lensing. Any hints of lensing will then be followed up with detailed
lens modelling and Monte Carlo simulations to provide the best
possible insight into the nature of the lens.