Related papers: Subaru through a different lens: microlensing by e…
It has been shown by Paczy\'nski that gravitational microlensing is potentially a useful method for detecting the dark constituents of the halo of our galaxy, if their mass lies in the approximate domain $10^{-6} < M/M_{\odot} < 10^{-1}$.…
From the nature of dark matter to the rate of expansion of our Universe, observations of distant galaxies distorted through strong gravitational lensing have the potential to answer some of the major open questions in astrophysics. Modeling…
The recent discovery of gravitational waves from mergers of $\sim 10 \, M_{\odot}$ black hole binaries has stimulated interested in Primordial Black Hole dark matter in this mass range. Microlensing and dynamical constraints exclude all of…
We investigate the possibility of identifying massive objects (lenses) in the Galactic Center region (GC) by means of pulsar timing. The well known intensity change due to microlensing is found to be less important. For typical stellar…
There has recently been interest in multi-Solar mass Primordial Black Holes (PBHs) as a dark matter (DM) candidate. There are various microlensing, dynamical and accretion constraints on the abundance of PBHs in this mass range. Taken at…
Dark Matter (DM) halos with masses below $\sim10^{8}$ $M_{\odot}$, which would help to discriminate between DM models, may be detected through their gravitational effect on distant sources. The same applies to primordial black holes,…
In this work, gravitational lensing in the weak and strong field limits is investigated for black hole spacetime within the framework of Hu-Sawicki $f(R)$ gravity. We employ the Ishihara et al. approach for weak lensing and adopt Bozza's…
If dark matter in the form of compact objects comprises a large fraction of the mass of the universe, then gravitational lensing effects on gamma-ray bursts are expected. We utilize BATSE and Ulysses data to search for lenses of different…
We investigate how Einstein rings and magnified arcs are affected by small-mass dark-matter haloes placed along the line-of-sight to gravitational lens systems. By comparing the gravitational signature of line-of-sight haloes with that of…
We study the gravitational lensing influence of a massive object in a dark matter halo, using a simple model of a point mass embedded in a spherical Navarro--Frenk--White halo. Building on the analysis of critical curves and caustics…
There is now abundant evidence for the presence of large quantities of unseen matter surrounding normal galaxies, including our own$^{1,2}$. The nature of this `dark matter' is unknown, except that it cannot be made of normal stars, dust,…
The cold dark matter scenario of hierarchical large-scale structure formation predicts the existence of abundant subhalos around large galaxies. However, the number of observed dwarf galaxies is far from this theoretical prediction,…
The existence of a cosmic neutrino background has been inferred indirectly from cosmological surveys through its effect on the linear-theory evolution of primordial density perturbations, as well as from measurements of the primordial…
Recently, Subaru Hyper Suprime-Cam (HSC) observations found 12 candidates for microlensing events. These events can be explained by primordial black holes (PBHs) with masses of $10^{-7}$-$10^{-6} M_\odot$ and a fraction of all dark matter…
The existence of strong lensing systems with Einstein radii (Re) covering the full mass spectrum, from ~1-2" (produced by galaxy scale dark matter haloes) to >10" (produced by galaxy cluster scale haloes) have long been predicted. Many…
Substructure in distant gravitational lens galaxies can be detected because it alters the brightnesses and shapes of the lensed images. The optical and radio flux ratios in the four-image lens B1422+231 imply that there is a \sim 10^4-10^7…
Microlensing is the tool of choice for the search and the analysis of compact halo objects ("MACHOs"), a still viable class of dark matter candidates at the galactic scale. Different analyses point towards an agreement in excluding dark…
Several gravitationally lensed quasars are observed with anomalous magnifications in pairs of images that straddle a critical curve. Simple theoretical arguments suggest that the magnification of these images should be approximately…
The subtle and unique imprint of dark matter substructure on extended arcs in strong lensing systems contains a wealth of information about the properties and distribution of dark matter on small scales and, consequently, about the…
With the increase in the number of observed gravitational wave (GW) signals, detecting strongly lensed GWs by galaxies has become a real possibility. Lens galaxies also contain microlenses (e.g., stars and black holes), introducing further…