Related papers: Ultralight boson cloud depletion in binary systems
Recent X-ray timing and spectral observations of black hole binaries in outburst have redefined methods for investigating the properties of Galactic black holes and the physics of accretion flows. High-frequency X-ray QPOs in 5 systems…
Based on the hyperboloidal framework, we research the dynamical process of charged de Sitter black holes scattered by a charged scalar field. From the linear perturbation analysis, with the coupling strength within a critical interval, the…
We calculate the quasinormal modes of a nonsingular spherically symmetric black hole effective model with holonomy corrections. The model is based on quantum corrections inspired by loop quantum gravity. It is covariant and results in a…
We perform the first nonlinear and self-consistent study of the merger and ringdown of a black hole mimicking object with stable light rings. To that end, we numerically solve the full Einstein-Klein-Gordon equations governing the head-on…
Ultralight scalar fields can experience runaway `superradiant' amplification near spinning black holes, resulting in a macroscopic `axion cloud' which slowly dissipates via continuous monochromatic gravitational waves. For a particular…
Mixing between ultralight bosons and the Standard Model photon may allow access to the hitherto invisible Universe. In the presence of plasma, photons are dressed with an effective mass which will influence the conversion between the two.…
During the tidal disruption of a star by a massive black hole (BH) of mass MBH <~ 10^7 Msun, stellar debris falls back to the BH at a rate well above the Eddington rate. A fraction of this gas is subsequently blown away from the BH,…
The detection of a stochastic gravitational wave background by pulsar-timing arrays indicates the presence of a population of supermassive black hole binaries. Although the observed spectrum generally matches predictions for orbital…
We derive an analytic phenomenological expression that predicts the final mass of the black-hole remnant resulting from the merger of a generic binary system of black holes on quasi-circular orbits. Besides recovering the correct…
This paper focuses on the dynamical implications of close supermassive black hole binaries both as an example of resonant phase mixing and as a potential explanation of inversions and other anomalous features observed in the luminosity…
We study the basic properties of accretion flows onto binary supermassive black holes, including the cases in which a circumbinary disk is misaligned with the binary orbital plane, by means of three-dimensional Smoothed Particle…
The bell-like ringdown of the gravitational field in the last stage of the merging of massive black holes is now routinely detected on earth by the last generation of gravitational wave detectors. Its spectrum is interpreted as a sum of…
Ultralight bosons are possible fundamental building blocks of nature, and promising dark matter candidates. They can trigger superradiant instabilities of spinning black holes (BHs) and form long-lived "bosonic clouds" that slowly dissipate…
We show that under certain astrophysical conditions a binary system consisting of two compact objects can be stabilized against indefinite shrinking of orbits due to the emission of gravitational radiation. In this case, the lighter binary…
In a recent paper we have shown that a minimally coupled, self-interacting scalar field of mass $m$ can form black holes of mass $M=\sqrt{3}/(4m)$ (in Planck units). If dark matter is composed by axions, they can form miniclusters that for…
Ultralight dark photons predicted in several Standard Model extensions can trigger the superradiant instability around rotating black holes if their Compton wavelength is comparable to the Blackhole radius. Consequently, the angular…
Supersymmetry predicts multiple flat directions, some of which carry a net baryon or lepton number. Condensates in such directions form during inflation and later fragment into Q-balls, which can become the building blocks of primordial…
We study the superradiant scattering of gravitational waves by a nearly extremal black hole (dimensionless spin $a=0.99$) by numerically solving the full Einstein field equations, thus including backreaction effects. This allows us to study…
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.…
The coalescence of a binary black hole can be accompanied by a large gravitational recoil due to anisotropic emission of gravitational waves. A recoiling supermassive black hole (SBH) can subsequently undergo long-lived oscillations in the…