Related papers: Ultra-relativistic grazing collisions of black hol…
For a successful detection of gravitational waves by LISA, it is essential to construct theoretical waveforms in a reliable manner. We discuss gravitational waves from an extreme mass ratio binary system which is expected to be a promising…
We study the properties of the outgoing gravitational wave produced when a non-spinning black hole is excited by an ingoing gravitational wave. Simulations using a numerical code for solving Einstein's equations allow the study to be…
We consider collisions between massive (electrons) and massless (photons) particles near the horizon of a rotating black hole. Similarly to collisions between massive particles, the infinite energy in the centre of mass frame occurs in some…
The ringdown gravitational wave signal arising e.g., in the final stage of a black hole binary merger, contains important information about the properties of the remnant, and can potentially be used to perform clean tests of general…
We compute the gravitational waveform emitted during the transition from quasi-spherical inspiral to plunge, merger and ringdown for a system of two black holes in the extreme mass ratio limit, where the primary is spinning and the…
We compute the gravitational radiation generated in the evolution of a family of close binary black hole configurations, using a combination of numerical and perturbative approximation methods. We evolve the binaries with spins, $s$,…
One proposed black hole formation channel involves hierarchical mergers, where black holes form through repeated binary mergers. Previous studies have shown that such black holes follow a near-universal spin distribution centered around…
The past decade has transformed our ability to observe the Universe. Via gravitational waves, merging black holes and neutron stars can now be directly detected, offering unprecedented opportunities to test General Relativity and explore…
We present a study of spinning black hole binaries focusing on the spin dynamics of the individual black holes as well as on the gravitational recoil acquired by the black hole produced by the merger. We consider two series of initial spin…
We investigate quadratic quasinormal mode coupling in black hole spacetime through numerical simulations of single perturbed black holes using both numerical relativity and second-order black hole perturbation theory. Focusing on the…
At the Kavli Institute for Theoretical Physics, participants of the rapid response workshop on the gravitational wave background explored discrepancies between experimental results and theoretical models for a background originating from…
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…
We review the theoretical aspects of gravitational lensing by black holes, and discuss the perspectives for realistic observations. We will first treat lensing by spherically symmetric black holes, in which the formation of infinite…
We study gravitational waves from a stellar-mass binary orbiting a spinning supermassive black hole, a system referred to as a binary extreme mass ratio inspiral (b-EMRI). We use Dixon's formalism to describe the stellar-mass binary as a…
In this exploratory study, we demonstrate the capability of the numerical-relativity code BAM to simulate fully relativistic black-hole binary-single and binary-binary encounters. While previous work has demonstrated the general capability…
Several models of physics beyond the Standard Model predict the existence of new ultralight bosons. This thesis investigates a way to discover such particles through observations of gravitational waves from binary black holes. This is…
Gravitational waves open the possibility to investigate the nature of compact objects and probe the horizons of black holes. Some models of modified gravity predict the presence of horizonless and singularity-free compact objects. Such dark…
Supermassive black hole binary mergers generate a stochastic gravitational wave background detectable by pulsar timing arrays. While the amplitude of this background is subject to significant uncertainties, the frequency dependence is a…
We demonstrate that in binary black hole mergers there is a direct correlation between the frequency of the gravitational wave at peak amplitude and the mass and spin of the final black hole. This correlation could potentially assist with…
In the dense regions of star clusters, close encounters with black holes (BHs) can occur giving rise to a new class of gravitational-wave (GW) signals. Binary-single encounters between three BHs are expected to dominate the rate of signals…