Abstract: | I will review the status of the space-based Laser Interferometer Space Antenna (LISA) and its science goals. LISA will detect gravitational waves in the frequency range 10^−4Hz<f<1Hz, a region of the spectrum populated by a large variety of astrophysical sources. Among these, a major role will be played by the mergers of massive black holes, which LISA will detect up to very large redshift z∼10−20. I will focus on the physics of these sources, as well as on how their detection by LISA will shape our understanding of astrophysics, cosmology and fundamental physics. |