Video URL http://pirsa.org/21110032
Mergers of compact objects are among the most violent events in the Universe. At close separations, compact binaries emit gravitational waves, releasing enormous amounts of energy until they merge. When matter is present in the system, the event might be accompanied by electromagnetic emission, which can span the entire electromagnetic spectrum. Multi-messenger observations by gravitational-wave detectors and electromagnetic telescopes have opened a new avenue to understand the nature of spacetime and its interaction with matter. In this talk, I will discuss recent efforts to connect first-principle calculations with the electromagnetic radiation emitted in compact binary mergers through general-relativistic magnetohydrodynamic simulations. In particular, I will focus on the relativistic outflows produced in binary neutron star systems and on electromagnetic signatures of supermassive binary black-hole mergers.