Related papers: Finding gravitational-wave black holes with parall…
Recent studies suggest that numerous intermediate-mass black holes (IMBHs) may wander undetected across the Universe, emitting little radiation. These IMBHs largely preserve their birth masses, offering critical insights into the formation…
We constrain the abundance of primordial black holes (PBH) using 2622 microlensing events obtained from 5-years observations of stars in the Galactic bulge by the Optical Gravitational Lensing Experiment (OGLE). The majority of microlensing…
The first discovery of the gravitational wave (GW) event, GW150914, suggests a higher merger rate of black-hole (BH) binaries. If this is true, a number of BH binaries will be observed via the second-generation GW detectors, and the…
We investigate how central black holes (BHs) inhabited in galactic dark halos could affect strong gravitational lensing. The distribution of integral lensing probability with image separations are calculated for quasars of redshift 1.5 by…
The natal kick velocity distribution for black holes (BHs) is unknown regardless of its importance for understanding the BH formation process. Gravitational microlensing is a unique tool for studying the distribution of BHs in our Galaxy,…
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…
Stellar microlensing observations tightly constrain compact object dark matter in the mass range $(10^{-11} - 10^{3}) M_{\odot}$. Primordial Black Holes (PBHs) form clusters, and it has been argued that these microlensing constraints are…
Gravitational waves (GWs) may be magnified or de-magnified due to lensing. This phenomenon will bias the distance estimation based on the matched filtering technique. Via the multi-sphere ray-tracing technique, we study the GW magnification…
Primordial black holes (PBHs) hidden in the incredible bulk of the dark dimension could escape constraints from non-observation of their Hawking radiation. Since these five-dimensional (5D) PBHs are bigger, colder, and longer-lived than…
Using ground-based gravitational-wave detectors, we probe the mass function of intermediate-mass black holes (IMBHs) wherein we also include BHs in the upper mass gap $\sim 60-130~M_\odot$. Employing the projected sensitivity of the…
We estimate the rate of gravitational microlensing events of cluster stars due to black holes (BHs) in the globular cluster NGC 5139 ($\omega Cen$). Theory and observations both indicate that $\omega Cen$ may contain thousands of BHs, but…
The primordial black hole (PBH) comprising full dark matter (DM) abundance is currently allowed if its mass lies between $10^{-16}M_{\odot} \lesssim M \lesssim 10^{-11} M_{\odot}$. This lightest mass range is hard to be probed by ongoing…
Some previous studies have suggested that massive and intermediate-mass primordial black holes (PBHs) could comprise a substantial fraction of dark matter in the Universe. Such black holes, if they existed in the Milky Way halo, would give…
The simplest interpretation of the microlensing events observed towards the Large Magellanic Cloud is that approximately half of the mass of the Milky Way halo is in the form of MAssive Compact Halo Objects with $M \sim 0.5 M_{\odot}$. This…
In this paper, we discuss how globular clusters (GCs) structural and observational properties can be used to infer the presence of a black hole system (BHS) inhabiting their inner regions. We propose a novel way to identify the BHS size,…
Numerous microlensing survey programs have constrained the possibility of dark matter existing in the form of compact objects within the Galactic halo. These constraints on the dark matter fraction were derived under the assumption of…
Inspirals and mergers of black hole (BHs) and/or neutron star (NSs) binaries are expected to be abundant sources for ground-based gravitational-wave (GW) detectors. We assess the capabilities of Advanced LIGO and Virgo to measure component…
Gravitational wave measurements will provide insight into the population of coalescing compact binaries throughout the universe. We describe and demonstrate a flexible parametric method to infer the event rate as a function of compact…
Most stellar remnants so far have been found in binary systems, where they interact with matter from their companions. Isolated neutron stars and black holes are difficult to find as they are dark, yet they are predicted to exist in our…
A galaxy halo may contain a large number of intermediate mass black holes (IMBHs) with masses in the range of 10^{2-6} solar mass. We propose to directly detect these IMBHs by observing multiply imaged QSO-galaxy or galaxy-galaxy strong…