Stringent constraints on the light boson model with supermassive black hole spin measurements

TL;DR

This study uses supermassive black hole spin measurements to place stringent constraints on light boson models, excluding significant parameter regions for scalars and vectors, impacting dark matter theories.

Contribution

It provides new observational constraints on light boson masses using supermassive black hole data, especially for vector bosons and QCD axions, improving previous bounds.

Findings

Excluded light boson mass range from 10^{-22} eV to 10^{-17} eV.

Significantly constrained fuzzy dark matter parameter space.

Ruled out QCD axions with masses around 3×10^{-19} eV to 10^{-17} eV.

Abstract

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.