Physics Colloquium: Illuminating the Dark Universe with Gravitational Waves

Dr. Alessandra Buonanno, Max Planck Institute for Gravitational Physics

Abstract: For centuries, we have explored the Universe and discovered novel astrophysical sources and phenomena only through the observation of electromagnetic waves (gamma rays, X-rays, optical, infrared, radio waves). In 2015, we observed the first gravitational wave passing through the Earth produced by the merger of two stellar-mass black holes. Such an event has provided us with a remarkable confirmation of the general theory of relativity by Albert Einstein, and ushered in the era of gravitational-wave astronomy. Since then, about one hundred gravitational waves have been detected, including the gravitational signal produced by the coalescence of two neutron stars, accompanied by a plethora of electromagnetic counterparts observed by numerous telescopes around the world. In this talk, I will highlight how the novel astronomical messengers are already unveiling distinctive properties of the most extreme astrophysical objects in the Universe, and discuss the discovery potential of future observatories in space and on the ground, which will open new frequency bandwidths.