Related papers: A Distant Origin For Magnified LIGO/Virgo Black Ho…
The discovery of gravitational wave radiation from merging black holes (BHs) also uncovered BHs with masses in the range of ~20-160 Msun. In contrast, the most massive Galactic stellar-mass BH currently known has a mass ~21 Msun. While…
We conduct a thorough Bayesian analysis of the possibility that the black hole merger events seen in gravitational waves are primordial black hole (PBH) mergers. Using the latest merger rate models for PBH binaries drawn from a lognormal…
We discuss the effect of clustering for the determination of the merger rate of binary black holes in the LIGO mass range. While for a Poissonian initial distribution, and assuming isolated binaries, the allowed fraction of Primordial Black…
Regardless of their initial spins, the merger of two roughly equal mass black holes (BHs) produces a remnant BH of dimensionless spin $0.69$. Such remnants can merge with other BHs in dense stellar environments and produce hierarchical…
Models for black hole (BH) formation from stellar evolution robustly predict the existence of a pair-instability supernova (PISN) mass gap in the range $\sim50$ to $\sim120$ solar masses. This theoretical prediction is supported by the…
The population of binary black hole (BBH) mergers observed by the LIGO-Virgo-KAGRA (LVK) collaboration offers a window into the cosmic evolution of compact binaries and their formation. We employ the semi-analytic population-synthesis code…
One of the seemingly strongest constraints on the fraction of dark matter in the form of primordial black holes (PBH) of ${\cal O}$(10)$\,M_\odot$ relies on the merger rate inferred from the binary BH merger events detected by LIGO/Virgo.…
LIGO/Virgo has detected several binary black hole (BBH) merger events that may have originated in the accretion disks of Active Galactic Nuclei (AGN). These events require individual black hole masses that fall within the pair instability…
The binary black hole mergers observed by LIGO-Virgo gravitational-wave detectors pose two major challenges: (i) how to produce these massive black holes from stellar processes; and (ii) how to bring them close enough to merge within the…
The population of black holes observed via gravitational waves currently covers the local universe up to a redshift $z\lesssim 1$, for the most massive merging binaries, or $z\lesssim 0.25$ for low-mass BH binaries (BBH). Evolution of the…
The spins of merging binary black holes offer insights into their formation history. Recently it has been argued that in isolated binary evolution of two massive stars the firstborn black hole is slowly rotating, whilst the progenitor of…
We show how LIGO is expected to detect coalescing binary black holes at $z>1$, that are lensed by the intervening galaxy population. Gravitational magnification, $\mu$, strengthens gravitational wave signals by $\sqrt{\mu}$, without…
We use the gravitational wave signals from binary black hole merger events observed by LIGO and Virgo to reconstruct the underlying mass and spin distributions of the population of merging black holes. We reconstruct the population using…
Observations have shown that the majority of massive stars, progenitors of black holes (BHs), have on average more than one stellar companion. In triple systems, wide inner binaries can be driven to a merger by the third body due to…
We explore the masses, merger rates, eccentricities, and spins for field binary black holes driven to merger by a third companion through the Lidov-Kozai mechanism. Using a population synthesis approach, we model the creation of…
Mainly motivated by the recent GW190521 mass gap event which we take as a benchmark point, we critically assess if binaries made of a primordial black hole and a black hole of astrophysical origin may form, merge in stellar clusters and…
We examine the distribution of masses of black holes in transient low mass X-ray binary systems. A Bayesian analysis suggests that it is probable that six of the seven systems with measured mass functions have black hole masses clustered…
The two binary black-hole (BBH) coalescences detected by LIGO, GW150914 and GW151226, were relatively nearby sources, with a redshift of ~0.1. As the sensitivity of Advanced LIGO and Virgo increases in the next few years, they will…
Using the Binary Population and Spectral Synthesis code BPASS, we have calculated the rates, timescales and mass distributions for binary black hole mergers as a function of metallicity. We consider these in the context of the recently…
While the Advanced LIGO and Virgo gravitational-wave experiments now regularly observe binary black hole mergers, the evolutionary origin of these events remains a mystery. Analysis of the binary black hole spin distribution may shed light…