The nature of dark matter is a long-standing open question in modern physics. Excitingly, black holes offer novel pathways to probe for ultra-light dark matter candidates by virtue of the superradiant instability. This classical phenomenon leads to the formation of a "gravitational atom'', i.e., long-lived condensates of ultra-light bosonic fields around astrophysical black holes.

In this talk, I will give an overview on black-hole superradiance, present the superradiant evolution of these gravitational atoms and discuss observational implications that will enable us to search for -- or place novel constraints on -- these dark matter candidates.