Results from the first all-sky search for boson clouds around spinning black holes using LIGO O3 data

We present results from the first all-sky search tailored for long-duration, quasi-monochromatic gravitational-wave signals emitted by ultralight scalar boson clouds around spinning black holes using data from the third observing run of Advanced LIGO. Our search spans gravitational-wave frequencies of 20-610 Hz, and optimizes the choice of the analysis parameters to account for uncertainties in the expected frequency evolution of the signal. We obtain a few outliers that are followed up in detail using two methods, one well-suited for almost monochromatic signals, and another well-adapted for spin-wandering ones. Though we do not find any evidence of gravitational waves, we place stringent upper limits that imply that scalar boson clouds younger than 1000 years, formed by bosons with mass ~1e-13eV, are not likely to exist in our Galaxy, and that show the maximum distance reach as a function of boson mass for a population of black holes with given distributions for mass and spin.