Related papers: Black Hole Binary Formation in the Expanding Unive…
Hierarchical structure formation inevitably leads to the formation of supermassive binary black holes (BBHs) with a sub-parsec separation in galactic nuclei. However, to date there has been no unambiguous detection of such systems. In an…
Population III (Pop. III) binary stars likely produced the first stellar-born binary black hole (BBH) mergers in the Universe. Here, we quantify the main sources of uncertainty for the merger rate density evolution and mass spectrum of Pop.…
Coalescing massive black hole binaries (MBHBs) of $10^{4-7} \rm M_{\odot}$, forming in the aftermath of galaxy mergers, are primary targets of the space mission LISA, the {\it Laser Interferometer Space Antenna}. An assessment of LISA…
As the sensitivity of current and future gravitational-wave detectors improves, it will become possible to measure the evolution of the binary black hole merger rate with redshift. Here, we combine detailed fits to state-of-the-art…
The possible formation mechanisms of massive close binary black holes (BHs) that can merge in the Hubble time to produce powerful gravitational wave bursts detected during advanced LIGO O1 and O2 science runs include the evolution from…
Supermassive black hole binaries (SMBHs) are expected to result from galaxy mergers, and thus are natural byproducts (and probes) of hierarchical structure formation in the Universe. They are also the primary expected source of…
We present a new approach to the problem of binary black holes in the pre-coalescence stage, i.e. when the notion of orbit has still some meaning. Contrary to previous numerical treatments which are based on the initial value formulation of…
The LIGO-Virgo-KAGRA (LVK) collaboration has detected over 150 confirmed gravitational wave events through O4a. Binary black hole (BBH) systems represent the overwhelming majority of these observations. We construct a model for the…
We analyze the dynamical evolution of binary stars that interact with a static background of single stars in the environment of a massive black hole (MBH). All stars are considered to be single mass, Newtonian point particles. We follow the…
We study the orbital evolution of black hole (BH) binaries in quadruple systems, where the tertiary binary excites large eccentricity in the BH binary through Lidov-Kozai (LK) oscillations, causing the binary BHs to merge via gravitational…
We revisit the three black hole scenario with numerical relativity techniques to study hierarchical configurations where the inner binary contains highly spinning black holes. We find that the merger time of the binary gets a delay (with a…
We can be biased against observing massive black holes to merge in the local universe as the bounds on the maximum black hole mass ($M_{BH}^{\rm max}$) depends on the assumptions regarding the metallicity evolution of the star forming gas…
Primordial black holes (PBHs) with log-normal mass spectrum with masses up to $\sim 10^4-10^5 M_\odot$ can be created after QCD phase transition in the early Universe at $z\sim 10^{12}$ by the modified Affleck-Dine baryogenesis. Using a…
Evidence has been mounting for the existence of black holes with masses from 10^2 to 10^4 M_Solar associated with stellar clusters. Such intermediate-mass black holes (IMBHs) will encounter other black holes in the dense cores of these…
Astrophysical black holes could be nearly extremal (that is, rotating nearly as fast as possible); therefore, nearly extremal black holes could be among the binaries that current and future gravitational-wave observatories will detect.…
In the case of zero-metal (population III or Pop III) stars, we show that the total mass of binary black holes from binary Pop III star evolution can be $\sim 150 \,M_{\odot}$, which agrees with the mass of the binary black hole GW190521…
Supermassive black holes (SMBHs) are a ubiquitous component of the nuclei of galaxies. It is normally assumed that, following the merger of two massive galaxies, a SMBH binary will form, shrink due to stellar or gas dynamical processes and…
We perform the first fully nonlinear numerical simulations of black-hole binaries with mass ratios 100:1. Our technique for evolving such extreme mass ratios is based on the moving puncture approach with a new gauge condition and an optimal…
We compare the event rate density detected by LIGO to the comoving number density of isolated stellar progenitors and find a range for their formation redshift. Our limit depends on the threshold mass for making the black holes (BHs) but…
The LIGO/Virgo collaboration have by now detected the mergers of ten black hole binaries via the emission of gravitational radiation. The hypothesis that these black holes have formed during the cosmic QCD epoch and make up all of the…