SuperRad: Modeling the black hole superradiance gravitational waveform

Understand

Gravitational signatures of black hole superradiance are a unique probe of ultralight particles that are weakly-coupled to ordinary matter.

• The existence of an ultralight boson would lead spinning black holes with size comparable to the Compton wavelength of the boson to become superradiantly unstable to forming an oscillating cloud, spinning down the black hole, and radiating gravitational waves in the process.
• However, maximizing the chance of observing such signals or, in their absence, placing the strongest constraints on the existence of such particles, requires accurate theoretical predictions.
• In this work, we introduce a new gravitational waveform model, SuperRad, that models the dynamics, oscillation frequency, and gravitational wave signals of these clouds by combining numerical results in the relativistic regime with fits calibrated to analytical estimates, covering the entire parameter space of ultralight scalar and vector clouds with the lowest two azimuthal numbers ($m = 1$ and $2$).