One century after its formulation, Einstein's general relativity (GR) has made remarkable
predictions and turned out to be compatible with all experimental tests. Most of these tests …

Black hole superradiance is a powerful probe of light, weakly coupled hidden sector
particles. Many candidate particles, such as axions, generically have self-interactions that …

Advanced LIGO may be the first experiment to detect gravitational waves. Through
superradiance of stellar black holes, it may also be the first experiment to discover the QCD …

The demand to obtain answers to highly complex problems within strong-field gravity has
been met with significant progress in the numerical solution of Einstein's equations—along …

Massive vector fields feature in several areas of particle physics, eg, as carriers of weak
interactions, dark matter candidates, or an effective description of photons in a plasma. Here …

We study the growth and saturation of the superradiant instability of a complex, massive
vector (Proca) field as it extracts energy and angular momentum from a spinning black hole …

Ultralight bosons and axion-like particles appear naturally in different scenarios and could
solve some long-standing puzzles. Their detection is challenging, and all direct methods …

The process of superradiance can extract angular momentum and energy from astrophysical
black holes (BHs) to populate gravitationally bound states with an exponentially large …

We study extreme mass-ratio binary systems in which a stellar mass compact object spirals
into a supermassive black hole surrounded by a scalar cloud. Scalar clouds can form …

We compute the quasi-bound state spectra of ultralight scalar and vector fields around
rotating black holes. These spectra are determined by the gravitational fine structure …