Massive bosons, such as light scalars and vector bosons, can lead to instabilities of rotating black holes by the superradiance effect, which extracts energy and angular momentum from rapidly-rotating black holes effectively. This process results in spinning-down of black holes and the formation of boson clouds around them. In this work, we used the masses and spins of supermassive black holes measured from the ultraviolet/optical or X-ray observations to constrain the model parameters of the light bosons. We find that the mass range of light bosons from $10^{-22}$ eV to $10^{-17}$ eV can be largely excluded by a set of supermassive black holes (including also the extremely massive ones OJ 287, Ton 618 and SDSS J140821.67+025733.2), particularly for the vector boson scenario, which eliminates a good fraction of the so-called fuzzy dark matter parameter regions. For the scalar bosons with self-interaction, most part of the mass range from $\sim 3 \times 10^{-19}$ eV to $10^{-17}$ eV with a decay constant $f_a > 10^{15}$ GeV can be excluded, which convincingly eliminate the QCD axions at these masses.
Probing Boson Clouds with Supermassive Black Hole Binaries
Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；School of Physics Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；Center for High Energy Physics, Peking University（北京大学高能物理中心）
Upper limits on microhertz gravitational waves from supermassive black-hole binaries using PSR J1909-3744 data from the second IPTA data release
Xinjiang Astronomical Observatories, Chinese Academy of Sciences（中国科学院新疆天文台）；University of Chinese Academy of Sciences（中国科学院大学）；Institute of Optoelectronic Technology, Lishui University（丽水学院光电技术研究所）
Testing solitonic boson star interpretations of Sagittarius A* with near-infrared flare astrometry
Beihang University（北京航空航天大学）；Ningbo University（宁波大学）；Peng Huanwu Collaborative Center for Research and Education, Beihang University（彭桓武研究中心，北京航空航天大学）；Beijing Normal University（北京师范大学）；Peking University（北京大学）
