Speaker
Description
Through black hole superradiance, ultralight bosonic fields may form macroscopic clouds around rotating black holes. Extreme-mass-ratio inspirals (EMRIs), among the primary targets of future space-based gravitational-wave detectors, provide a unique opportunity to probe such environments. We extend the relativistic perturbative framework for EMRIs within scalar clouds from circular, equatorial motion to eccentric and inclined orbits. Working on a Schwarzschild black-hole background, we compute the scalar energy and angular-momentum scattered off to infinity and absorbed at the event horizon. We show that eccentricity induces a dense sequence of strong-field resonances near the last stable orbit, while orbital inclination significantly modifies the fluxes and resonant structure. By evolving the orbits adiabatically, we show that resonant transitions substantially enhance the exchange of energy and angular momentum between the orbit and the cloud, amplifying the accumulated gravitational-wave dephasing relative to circular motion. Our results highlight the importance of extending environmental calculations beyond circular, equatorial motion when modelling realistic EMRIs.