All-sky search for gravitational wave emission from scalar boson clouds around spinning black holes in LIGO O3 data

Abstract

This paper describes the first all-sky search for long-duration, quasi-monochromatic gravitationalwave signals emitted by ultralight scalar boson clouds around spinning black holes using data from the third observing run of Advanced LIGO. We analyze the frequency range from 20 Hz to 610 Hz, over a small frequency derivative range around zero, and use multiple frequency resolutions to be robust towards possible signal frequency wanderings. Outliers from this search are followed up using two different methods, one more suitable for nearly monochromatic signals, and the other more robust towards frequency fluctuations. We do not find any evidence for such signals and set upper limits on the signal strain amplitude, the most stringent being ≈ 10 −25 at around 130 Hz. We interpret these upper limits as both an "exclusion region" in the boson mass/black hole mass plane and the maximum detectable distance for a given boson mass, based on an assumption of the age of the black hole/boson cloud system.

Ionization of Gravitational Atoms

“…It is worth noting that, at the cross-over point k = 2πµ 2 M * , the de Broglie wavelength of the scalar field equals the Bohr radius of the gravitational atom, 2π/k = r c . 10 For k 2πµ 2 M * , the energy flux diverges as 1/v, just like in the particle case, but with a smaller normalization. For k 2πµ 2 M * , instead, the energy flux is independent of v and takes the very natural form A * ρc, if we restore a factor of c. This indeed matches the result for the low-energy cross section for a massless field [39][40][41][42].…”

“…For isolated gravitational atoms, there are essentially two ways of inferring the presence of these boson clouds. First, rotating clouds will emit gravitational waves [7] that can be looked for in continuous-wave searches [10]. Second, the clouds extract spin from their parent black holes and this spin-down can be inferred statistically in a population of rotating black holes [7,[11][12][13][14][15].…”

Axion cosmology in the presence of non-trivial Nambu-Goldstone modes

“…An interesting possibility of detecting ultralight dark matter clouds surrounding black holes by using gravitational wave emission has been pointed out [5]. The method appears to work due to a recent announcement of the bound in the mass range ∼ 10 −13 eV (frequency 20 ∼ 610 Hz) for scalar dark matter [14].…”

Axion cloud evaporation during inspiral of black hole binaries -- the effects of backreaction and radiation

“…This implies that the resonance band shrinks as the angular momentum is transferred from the cloud to the orbital motion. Thus, we have the diagonal term of the Hamiltonian (19) that describes the transition between the levels separated by the hyperfine split as…”