Related papers: Black hole binaries and light fields: Gravitationa…
Rotating axisymmetric objects amplify incoming waves by superradiant scattering. When enclosed in a cavity, the repeated interaction of a confined field with the object may trigger superradiant instabilities. Rotating binaries are…
Gravitational waves emitted by black hole binary inspiral and mergers enable unprecedented strong-field tests of gravity, requiring accurate theoretical modelling of the expected signals in extensions of General Relativity. In this paper we…
Binary systems of compact objects in close orbit around a supermassive black hole (SMBH) may form in galactic nuclei, providing a unique environment to probe strong-gravity tidal effects on the binary's dynamics. In this work, we…
Binary black hole coalescence has its peak of gravitational wave generation during the "plunge," the transition from quasicircular early motion to late quasinormal ringing. Although advances in numerical relativity have provided plunge…
We consider two scalar fields interacting through a $\chi^*\chi\phi^*\phi$ term in the presence of a Reissner-Nordstrom black hole. Initially, only $\chi$ particles are present. We find that the produced $\phi$ particles are localized in a…
A numerical solution scheme for the Einstein field equations based on generalized harmonic coordinates is described, focusing on details not provided before in the literature and that are of particular relevance to the binary black hole…
We derive the scalar waveform generated by a binary of nonspinning compact objects (black holes or neutron stars) in a general class of scalar-tensor theories of gravity. The waveform is accurate to 1.5 post-Newtonian order [$O((v/c)^3)$]…
Recently, gravity duals for certain Galilean-invariant conformal field theories have been constructed. In this paper, we point out that the spectrum of the particle number operator in the examples found so far is not a necessary consequence…
While an axion-clouded black hole (BH) encounters a pulsar (PSR) or has a PSR companion, a "gravitational molecule" can be formed. In such a system, the axion cloud evolves at the binary hybrid orbitals, as it happens at microscopic level…
Scalar-tensor theories are among the simplest extensions of general relativity. In theories with light scalars, deviations from Einstein's theory of gravity are determined by the scalar mass m_s and by a Brans-Dicke-like coupling parameter…
Superradiant instabilities may create clouds of ultralight bosons around rotating black holes, forming so-called "gravitational atoms." It was recently shown that the presence of a binary companion can induce resonant transitions between…
Light bosonic degrees of freedom have become a serious candidate for dark matter. The evolution of these fields around curved spacetimes is poorly understood but is expected to display interesting effects. In particular, the interaction of…
We numerically construct a family of stationary, axisymmetric black hole solutions in Einstein-Born-Infeld theory, incorporating both electric charge and rotation. Our results indicate that when nonlinear electromagnetic effects are weak,…
We develop a full four-dimensional numerical code to study scalar gravitational radiation emitted from binary systems and probe the Vainshtein mechanism in situations that break the static and spherical symmetry, relevant for binary pulsars…
We study the imprints of new ultralight particles on the gravitational-wave signals emitted by binary black holes. Superradiant instabilities may create large clouds of scalar or vector fields around rotating black holes. The presence of a…
We find the gravitational resonance (quasinormal) modes of the higher dimensional Schwarzschild and Reissner-Nordstrem black holes. The effect on the quasinormal behavior due to the presence of the $\lambda$ term is investigated. The QN…
Irrotational ow of a spherical thin liquid layer surrounding a rigid core is described using the defocusing nonlinear Schrodinger equation. Accordingly, azimuthal moving nonlinear waves are modeled by periodic dark solitons expressed by…
We present a detailed, fully nonlinear study of binary systems involving one black hole and one boson star, considering the effects of both a quartic self-interaction and a solitonic potential for the scalar field. First, we show the…
The quasinormal mode spectrum of gravitational waves emitted during the black hole ringdown relaxation phase, following the merger of a black hole binary, is a crucial target of gravitational wave astronomy. By considering causality…
We show how gravitational-wave observations of binary black hole (BBH) mergers can constrain the physical characteristics of a scalar field cloud parameterized by mass $\tilde{\mu}$ and strength $\phi_0$ that may surround them. We…