Tidal deformability of dressed black holes and tests of ultralight bosons in extended mass ranges

The deformability of a compact object under the presence of a tidal perturbation is encoded in the tidal Love numbers (TLNs), which vanish for isolated black holes in vacuum. We show that the TLNs of black holes surrounded by matter fields do not vanish and can be used to probe the environment around binary black holes. In particular, we compute the TLNs for the case of a black hole surrounded by a scalar condensate under the presence of scalar and vector tidal perturbations, finding a strong power-law behavior of the TLN in terms of the mass of the scalar field. Using this result as a proxy for gravitational tidal perturbations, we show that future gravitational-wave detectors like the Einstein Telescope and LISA can impose stringent constraints on the mass of ultralight bosons that condensate around black holes due to accretion or superradiance. Interestingly, LISA could measure the tidal deformability of dressed black holes across the range from stellar-mass (approximate to 10(2)M(circle dot)) to supermassive (approximate to 10(7)M(circle dot)) objects, providing a measurement of the mass of ultralight bosons in the range (10(-17) - 10(-13)) eV with less than 10% accuracy, thus filling the gap between other superradiance-driven constraints coming from terrestrial and space interferometers. Altogether, LISA and Einstein Telescope can probe tidal effects from dressed black holes in the combined mass range (10(-17) - 10(-11)) eV.

Automated summary

Research shows that tidal Love numbers (TLNs) of black holes surrounded by matter fields are non-zero and can be used to probe the environment around binary black holes. By computing TLNs under tidal perturbations, stringent constraints can be imposed on the mass of ultralight bosons condensing around black holes, providing measurements for future gravitational-wave detectors. Additionally, the mass range of ultralight bosons can be probed by LISA and Einstein Telescope across a broad spectrum, enhancing our understanding of tidal effects from dressed black holes.