相关论文: Adiabatic evolution of the self-interacting axion …

Superradiant instability can form clouds around rotating black holes (BHs) composed of ultralight bosonic fields, such as axions. A BH with such a cloud in a binary system exhibits rich phenomena, and gravitational waves (GWs) from the BH…

There are strong interests in considering ultra-light scalar fields (especially axion) around a rapidly rotating black hole because of the possibility of observing gravitational waves from axion condensate (axion cloud) around black holes.…

We report some new interesting features of the dynamics of a string axion field (i.e., a (pseudo-)scalar field with tiny mass with sine-Gordon-type self-interaction) around a rotating black hole in three respects. First, we revisit the…

Ultra-light particles, such as axions, form a macroscopic condensate around a highly spinning black hole by the superradiant instability. Due to its macroscopic nature, the condensate opens the possibility of detecting the axion through…

Motivated by possible existence of stringy axions with ultralight mass, we study the behavior of an axion field around a rapidly rotating black hole (BH) obeying the sine-Gordon equation by numerical simulations. Due to superradiant…

It has recently been suggested that the presence of a plenitude of light axions, an Axiverse, is evidence for the extra dimensions of string theory. We discuss the observational consequences of these axions on astrophysical black holes…

Through the black hole (BH) superradiance, ultralight bosons can form dense clouds around rotating Kerr BHs. Certain ultralight bosons, such as axions and axion-like particles (promising dark matter candidates), naturally possess…

We study the dynamical evolution of superradiant instabilities of rotating black holes for multiple axion fields with comparable masses, motivated by string theory constructions, which typically exhibit a large number of light axions, with…

Boson clouds around black holes exhibit interesting physical phenomena through the Penrose process of superradiance, leading to black hole spin-down. Axionic clouds are of particular interest, since the axion Compton wavelength could be…

Spinning black holes can transfer a significant fraction of their energy to ultralight bosonic fields via superradiance, condensing them in a co-rotating structure or "cloud". This mechanism turns black holes into powerful particle…

Oscillating clouds of ultralight bosons can grow around spinning black holes through superradiance, extracting energy and angular momentum, and eventually dissipating through gravitational radiation. Gravitational wave detectors like LIGO,…

Motivated by possible existence of string axions with ultralight masses, we study gravitational radiation from an axion cloud around a rotating black hole (BH). The axion cloud extracts the rotation energy of the BH by superradiant…

We analyze the dynamics and observational signatures of axion clouds formed via the superradiant instability around primordial black holes, focusing on the mass range $10^{14}-10^{18}$ kg where the latter may account for all the dark…

Black hole superradiance is a powerful probe of light, weakly-coupled hidden sector particles. Many candidate particles, such as axions, generically have self-interactions that can influence the evolution of the superradiant instability. As…

Gravitational waves from condensates of ultra-light particles, such as axion, around rotating black holes are a promising probe to search for unknown physics. For this purpose, we need to characterize the signal to detect the gravitational…

Superradiant clouds may develop around a rotating black hole, if there is a bosonic field with Compton wavelength comparable to the size of the black hole. In this paper, we investigate the effects of the cloud on the orbits of nearby…

An axion cloud surrounding a supermassive black hole can be naturally produced through the superradiance process. Its existence can be examined by the axion induced birefringence effect. It predicts an oscillation of the electric vector…

Superradiant instability of rotating black holes (BHs) leads to the formation of a cloud of ultralight bosons, such as axions. When the BH with the cloud belongs to a binary system and is in an inspiraling orbit, the resonant transition…

Under some conditions, light boson fields grow exponentially around a rotating black hole, called the superradiance instability. We discuss effects of nonlinear interactions of the boson on the instability. In particular, we focus on the…

Light feebly-coupled bosonic particles can efficiently extract the rotational energy of rapidly spinning black holes on sub-astrophysical timescales via a phenomenon known as black hole superradiance. In the case of light axions, the feeble…