Probing Black Hole Mergers with LISA

The Laser Interferometer Space Antenna (LISA) is a gravitational wave observatory in the frequency window 0.1 mHz - 0.1 Hz, capable of observing black hole mergers throughout the Universe. I will discuss the potential of LISA high-redshift surveys for novel studies of black hole demographics, formation of cosmic structures, cosmology and detailed investigations of the behaviour of gravity in the strong non-linear regime.