The idea of stable, localized bundles of energy has strong appeal as a model for particles. In
the 1950s, John Wheeler envisioned such bundles as smooth configurations of …

We establish a generic, fully relativistic formalism to study gravitational-wave emission by
extreme-mass-ratio systems in spherically symmetric, nonvacuum black hole spacetimes …

Studies of black hole superradiance often focus on the growth of a cloud in isolation,
accompanied by the spin-down of the black hole. In this paper, we consider the additional …

Previous works have argued that future gravitational-wave detectors will be able to probe
the properties of astrophysical environments where binaries coalesce, including accretion …

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 develop a numerical approach to find asymptotically flat black hole solutions coupled to
anisotropic fluids, described by generic density profiles. Our model allows for a variety of …

The motion of S2, one of the stars closest to the Galactic Centre, has been measured
accurately and used to study the compact object at the centre of the Milky Way. It is …

The interaction of binary black hole mergers with their environments can be studied using
numerical relativity simulations. These start only a short finite time before merger, at which …

We use numerical simulations of scalar field dark matter evolving on a moving black hole
background to confirm the regime of validity of (semi) analytic expressions derived from first …

The compelling evidence for the detection of the stochastic gravitational wave background
by NANOGrav imposes constraints on the mass of compact cores of ultra-light dark matter …