Seminar: ‘Gravitational Lensing of Waves: a new window into cosmology and fundamental physics’

Speaker: Miguel Zumalacárregui from Max Planck Institute for Gravitational Physics (Albert Einstein Institute).

Venue&Time: Red Room / 3:00 PM

Abstract: Gravitational lensing, the bending of light by gravity, is essential for interpreting astronomical observations and provides key insight into astrophysics, cosmology, and fundamental physics. A new frontier in gravitational lensing intersects with another key prediction of Einstein’s theory: gravitational waves, fluctuations of space-time produced by the collision of black holes and neutron stars. Like light, gravitational waves are deflected and magnified by the intervening matter distribution, but their unique properties (low frequency, lack of absorption and ab-initio emission models) enable novel signatures and applications. I will present the phenomenology of lensed gravitational waves and the science they will deliver to identify high-redshift sources and probe dark-matter and new gravitational fields. As guiding example I will focus on GW231123: the first compelling lensed black hole merger candidate, its interpretation and consequences.