Related papers: Amplification of waves from a rotating body
We peform a study of gravitational waves emitted by inspiraling black holes in the context of quadratic gravity. By linearizing the field equations around a flat background, we demonstrate that all degrees of freedom satisfy wave-like…
This is an expanded version of my talk given at the international conference "Zeldovich-90". I start with a brief recollection of interactions with Zeldovich in the context of the study of relic gravitational waves. I then summarise the…
We discuss simple integration methods for the calculation of rotating black hole scattering resonances both in the complex frequency plane (quasinormal modes) and the complex angular momentum plane (Regge poles). Our numerical schemes are…
We develop a framework based on modern amplitude techniques to analyze emission and absorption effects in black hole physics, including Hawking radiation. We first discuss quantum field theory on a Schwarzschild background in the Boulware…
We use $N$-body simulations to investigate the excitation of bending waves in a Milky Way-like disc-bulge-halo system. The dark matter halo consists of a smooth component and a population of subhaloes while the disc is composed of thin and…
It has long been believed that accretion onto supermassive black holes powers quasars, but there has been relatively few observational constraints on the spins of the black holes. We address this problem by estimating the average radiative…
The gravitational waves and energy radiations from a spinning compact object with stellar mass in a circular orbit in the equatorial plane of a supermassive Kerr black hole are investigated in this paper. The effect how the spin acts on…
Both ultralight dark matter and exploring the quantum nature of black holes are all topics of great interest in gravitational wave astronomy at present. The superradiant instability allows an exotic compact object (ECO) to be surrounded by…
Some of the most prominent theoretical predictions of modern times, e.g., the Unruh effect, Hawking radiation, and gravity-assisted particle creation, are supported by the fact that various quantum constructs like particle content and…
Recently it was found that helical magnetized flows efficiently amplify Alfv\'en waves (Rogava et al. 2003, A&A, v.399, p.421). This robust and manifold nonmodal effect was found to involve regimes of transient algebraic growth (for purely…
Astrophysical environments are ubiquitous in the Universe; from accretion disks around black holes to galactic dark matter halos, distributions of astrophysical material veil the vast majority of Cosmos. Including environmental effects in…
We investigate the propagation of gravitational waves on a black hole background within the low energy effective field theory of gravity, where effects from heavy fields are captured by higher dimensional curvature operators. Depending on…
Generalizing to relativistic exponential scaling and using the theory of noise from quantum fluctuations, it has been shown that one vacuum (Rindler, Hartle-Hawking, or Gibbons-Hawking for the cases of the uniformly accelerated detector,…
We study the scalar radiation emitted by a source orbiting a Schwarzschild--anti--de Sitter black hole in circular geodesics. We obtain the emitted power using quantum field theory in curved spacetimes at tree level with reflective boundary…
The collapse of large-amplitude primordial curvature perturbations into planetary-mass primordial black holes generates a scalar-induced gravitational wave background in the $\mu $Hz frequency range that may be detectable by future Lunar…
We investigate the absorption and scattering of charged massive scalar waves by the Kerr-Newman black-bounce spacetime when the waves are incident along the rotation axis. Our findings indicate that a faster (slower) rotating spacetime or a…
Gravity simulators are laboratory systems where small excitations like sound or surface waves behave as fields propagating on a curved spacetime geometry. The analogy between gravity and fluids requires vanishing viscosity, a feature…
Ten short years ago, we had the rare privilege of witnessing the onset of a renaissance in science: humanity finally succeeded in its arduous quest to directly detect gravitational waves. This breakthrough did not occur in a vacuum: it was…
We initiate a general investigation into gravitational wave signatures of modifications to scattering of gravitational radiation from black holes. Such modifications may be present due to the quantum dynamics that makes black holes…
The possibility of extracting energy from a rotating black hole via the Blandford-Znajek mechanism represents a cornerstone of relativistic astrophysics. We present general-relativistic collisionless kinetic simulations of Kerr black-hole…