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 ∼3×10−19 eV to 10−17 eV with a decay constant fa>1015 GeV can be excluded, which convincingly eliminate the QCD axions at these masses.
@article{arxiv.2007.03222,
title = {Stringent constraints on the light boson model with supermassive black hole spin measurements},
author = {Lei Zu and Lei Feng and Qiang Yuan and Yi-Zhong Fan},
journal= {arXiv preprint arXiv:2007.03222},
year = {2020}
}