Detectability of gravitational atoms in black hole binaries with the Einstein Telescope
Phys. Rev. D 112, 024074 – Published 30 July, 2025
DOI: https://doi.org/10.1103/h7ld-vv9p
Abstract
Rotating black holes can amplify ultralight bosonic fields through superradiance, forming macroscopic clouds known as gravitational atoms. When the cloud forms around one of the components of a binary system, it can undergo a series of distinctive interactions, comprising both secular effects, such as dynamical friction or accretion, and resonant behavior. These processes are expected to leave a distinctive signature on the gravitational waveform emitted by the binary, whose detectability we investigate in this paper. To do so, we implement a numerical code that integrates these effects, computed within a Newtonian approximation, for small-to-intermediate mass-ratio binaries on circular equatorial orbits. Realistic waveforms incorporating these environmental influences are generated and analyzed using the Fisher-matrix formalism to evaluate the detectability of bosonic clouds with current and next-generation ground-based gravitational-wave observatories. Our results demonstrate the potential for gravitational-wave astronomy to probe the existence and properties of ultralight bosons.
