Related papers: Black hole induced spins from hyperbolic encounter…
In this paper, we use numerical relativity to study the spin induction effect within close hyperbolic encounters of initially spinning black holes. We review the initially non-spinning case and explore the cases of initially aligned,…
Scattering black holes spin up and gain mass through the re-absorption of orbital angular momentum and energy radiated in gravitational waves during their encounter. In this work, we perform a series of numerical relativity simulations to…
The orbits of two black holes which are initially unbound can be transformed into bound orbits by emitting gravitational waves during close encounters in a star cluster, which is called a gravitational wave (GW) capture. The effects of spin…
The spin of a black hole is an important quantity to study, providing a window into the processes by which a black hole was born and grew. Further, spin can be a potent energy source for powering relativistic jets and energetic particle…
The inner part of dense clusters of primordial black holes is an active environment where multiple scattering processes take place. Some of them give rise from time to time to bounded pairs, and the rest ends up with a single scattering…
The heaviest black holes discovered through gravitational waves have masses that are difficult to explain with current standard stellar models. This discrepancy may be due to a series of hierarchical mergers, where the observed black holes…
Cosmic strings that are attached to rapidly spinning black holes can extract significant amounts of rotational energy and angular momentum. Here we study the effect on primordial black holes, which are expected to form with one or more…
When two relativistically boosted, nonspinning black holes pass by one another on a scattering trajectory, we might expect the tidal interaction to spin up each black hole. We present the first exploration of this effect, appearing at…
Primordial black holes (PBHs) could account for all or part of dark matter, as well as for some LIGO events. We discuss the spins of primordial black holes produced in different cosmological scenarios, with the emphasis on recently…
Theoretical studies of angular momentum transport suggest that isolated stellar-mass black holes are born with negligible dimensionless spin magnitudes $\chi \lesssim 0.01$. However, recent gravitational-wave observations indicate $\gtrsim…
In the standard paradigm, astrophysical black holes can be described solely by their mass and angular momentum - commonly referred to as `spin' - resulting from the process of their birth and subsequent growth via accretion. Whilst the mass…
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…
When two black holes merge in a dense star cluster, they form a new black hole with a well-defined mass and spin. If that "second-generation" black hole remains in the cluster, it will continue to participate in dynamical encounters, form…
We consider black holes resulting from binary black hole mergers. By fitting to numerical results we construct analytic formulas that predict the mass and spin of the final black hole. Our formulas are valid for arbitrary initial spins and…
The angular momentum (spin) acquisition by a collapsing domain wall at the cosmological radiation-dominated stage is investigated. During the collapses, primordial black holes and their clusters can be born in various mass ranges. Spin…
Using recent results from numerical relativity simulations of black hole mergers, we revisit previous studies of cosmological black hole spin evolution. We show that mergers are very unlikely to yield large spins, unless alignment of the…
Independently from the formation mechanism of primordial black holes in the early Universe, their generation is accompanied by a ringdown phase during which they relax to a stationary configuration and gravitational waves under the form of…
Massive black holes appear to be present in the nuclei of almost all galaxies, but their genesis and evolution are not well understood. As astrophysical black holes are completely characterized by their masses and spins, the observed joint…
Primordial stellar-mass black holes, which may contribute to dark matter and to the observed LIGO binary black hole coalescences, are expected to be born with very low spins. Here we show that accretion mass gain by the components of a…
We investigate a new mechanism to create large curvature perturbations on small scales due to parameter resonance in a single-field inflationary model with a small periodic structure upon the potential. After reentering the horizon, the…