Related papers: Lensing Constraints on PBHs: Substellar to Interme…
If a significant fraction of dark matter is in the form of compact objects, they will cause microlensing effects in the gravitational wave (GW) signals observable by LIGO and Virgo. From the non-observation of microlensing signatures in the…
A long-standing problem in astrophysics is to measure the mass associated with galaxies. Gravitational lensing provides one of the cleanest ways to make this measurement. To date, the most powerful lensing probes of galactic mass have been…
Gravitational microlensing finds planets through their gravitational influence on the light coming from a more distant background star. The presence of the planet is then inferred from the tell-tale brightness variations of the background…
We investigate gravitational microlensing of point-like lenses surrounded by diffuse gas clouds. Besides gravitational bending, one must also consider refraction and absorption phenomena. According to the cloud density, the light curves may…
It is estimated that a star brighter than visual magnitude 17 is undergoing a detectable gravitational microlensing event, somewhere on the sky, at any given time. It is assumed that both lenses and sources are normal stars drawn from a…
The LIGO-Virgo gravitational-wave (GW) observation unveiled the new population of black holes (BHs) that appears to have an extended mass spectrum up to around $70M_\odot$, much heavier than the previously-believed mass range ($\sim…
Despite consistent progress in numerical simulations, the observable properties of galaxy clusters are difficult to predict ab initio. It is therefore important to compare both theoretical and observational results to a direct measure of…
The dark and dynamic parts of the Galaxy, including the bulk shape and movement of the Galactic Bulge and characteristics of dark compact object populations, such as a hypothetical population of primordial black holes (PBHs), are difficult…
The microlensing of background stars by compact objects in globular clusters is analyzed. The main strength of the proposed search is the direct relationship between the lens mass and the time scale of the microlensing event. The main…
Microlensing observations have now become a useful tool in searching for non--luminous astrophysical compact objects (brown dwarfs, faint stars, neutron stars, black holes and even planets). Originally conceived for establishing whether the…
Primordial black holes (PBHs) may form in the early stages of the Universe via the collapse of large density perturbations. Depending on the formation mechanism, PBHs may exist and populate today the galactic halos and have masses in a wide…
Gravitational lensing is one of a number of methods used to probe the distribution of dark mass in the Universe. On galactic scales, complementary techniques include the use of stellar kinematics, kinematics and morphology of the neutral…
Gravitational microlensing is unique in detecting binary black (BH) holes with wide (a few au) separations. Models predict that about $1\%$ of microlensing binaries should be due to binary BHs, and yet zero has been robustly identified.…
The mass function and statistics of binaries provide important diagnostics of the star formation process. Despite this importance, the mass function at low masses remains poorly known due to observational difficulties caused by the…
The gravitational microlensing light curves that reveal the presence of extrasolar planets generally yield the planet-star mass ratio and separation in units of the Einstein ring radius. The microlensing method does not require the…
Fast cosmological transients such as fast radio bursts (FRBs) and gamma-ray bursts (GRBs) represent a class of sources more compact than any other cosmological object. As such they are sensitive to significant magnification via…
Gravitational lensing of a gamma ray burst (GRB) by a single point mass will produce a second, delayed signal. Several authors have discussed using microlensed GRBs to probe a possible cosmological population of compact objects. We analyse…
Gravitational microlensing is a new technique for studying the surfaces of distant stars. A point mass lens, usually a low-mass star from the disk, will typically resolve the surface of a red giant in the Galactic bulge, as well as amplify…
We have monitored 8.6 million stars in the Large Magellanic Cloud for 1.1 years and have found 3 events consistent with gravitational microlensing. We place strong constraints on the Galactic halo content in the form of compact lensing…
We consider the feasibility of directly observing gravitational microlensing in extra-galactic sources, whose stars are not generally resolved. This precludes use of the simple optical depth to microlensing formulation, which is applicable…