Related papers: On the population III binary black hole mergers be…
The presence of supermassive black holes (SMBHs) at high redshifts ($z>5$), as revealed by James Webb Space Telescope (JWST), challenges standard black hole (BH) formation scenarios. We propose a mechanism in which non-annihilating dark…
We report on key studies on the dynamics of black holes (BHs) in gas-rich galaxy mergers that underscore the vital role played by gas dissipation in promoting BH inspiral down to the smallest scales ever probed with use of high-resolution…
The occurrence of pair-instability supernovae is predicted to prevent the formation of black holes with masses $\gtrsim 50 M_\odot$. Recent gravitational-wave detections in this mass range require an explanation beyond that of standard…
If binary intermediate-mass black holes (IMBHs; with masses between 100 and $10^4 \Msun$) form in dense stellar clusters, their inspiral will be detectable with the planned Laser Interferometer Space Antenna (LISA) out to several Gpc. Here…
The intermediate mass black hole range, $10\lesssim M_{\rm BH}^{}/M_\odot^{}\lesssim 10^{5} $, has long offered enticing possibilities for primordial black holes (PBH), with populations in this range postulated to be responsible for some of…
We report the formation of intermediate-mass black holes (IMBHs) in suites of numerical $N$-body simulations of Population III remnant black holes (BHs) embedded in gas-rich protogalaxies at redshifts $z\gtrsim10$. We model the effects of…
Binary neutron-star mergers will predominantly produce black-hole remnants of mass $\sim 3-4\,M_{\odot}$, thus populating the putative \emph{low mass gap} between neutron stars and stellar-mass black holes. If these low-mass black holes are…
In this work we investigate the merger rate of primordial black hole-neutron star (PBH-NS) binaries in two widely-studied modified gravity (MG) models: Hu-Sawicki $f(R)$ gravity and the normal branch of Dvali-Gabadadze-Porrati (nDGP)…
Black hole binaries formed dynamically in globular clusters are believed to be one of the main sources of gravitational waves in the Universe. Here, we use our new population synthesis code, cBHBd, to determine the redshift evolution of the…
Studying the formation and evolution of black hole binaries (BHBs) is essential for the interpretation of current and forthcoming gravitational wave (GW) detections. We investigate the statistics of BHBs that form from isolated binaries, by…
We have calculated the detectable merger rate of primordial black holes, as a function of the redshift, as well as the binary's mass ratio, total mass and chirp mass (observables that have not previously been explored in great detail for…
We investigate a hierarchical structure formation scenario describing the evolution of a Super Massive Black Holes (SMBHs) population. The seeds of the local SMBHs are assumed to be 'pregalactic' black holes, remnants of the first POPIII…
Spin and mass properties provide essential clues in distinguishing the origins of coalescing black holes (BHs). With a dedicated semiparametric population model for the coalescing binary black holes (BBHs), we identify two distinct…
We present a comprehensive parameter-space study of binary black hole (BBH) mergers using the SEOBNRv4\_opt waveform model. Our analysis spans $\sim 10^6$ simulated waveforms across a broad range of mass ratios \( q = \frac{m_1}{m_2} \in…
Black hole (BH) triples represent one of the astrophysical pathways for BH mergers in the Universe detectable by LIGO and VIRGO. We study the formation of BH triples via binary-binary encounters in dense clusters, showing that one-third of…
The recent discovery of the gravitational wave source GW150914 has revealed a coalescing binary black hole (BBH) with masses of $\sim 30~M_\odot$. Previous proposals for the origin of such a massive binary include Population III (PopIII)…
We derive a lower bound on the merger rate of primordial black hole (PBH) binaries by estimating the maximal fraction of binaries that were perturbed between formation in the early Universe and merger, and computing a conservative merger…
The primary and secondary masses of the binary black holes (BBH) reported by LIGO/Virgo are correlated with a narrow dispersion that appears to increase in proportion to mass. The mean binary mass ratio $1.45\pm0.07$ we show is consistent…
We focus on gravitational-wave events of binary black-hole mergers up to the third observing run with the minimum false alarm rate smaller than $10^{-5}\,{\rm yr}^{-1}$. These events tell us that the mass ratio of two black holes follows…
We use a 3-D relativistic SPH (Smoothed Particle Hydrodynamics) code to study mergers of black hole -- neutron star (BH--NS) binary systems with low mass ratios, adopting $M_{NS}/M_{BH} \simeq 0.1$ as a representative case. The outcome of…