Related papers: Probing dark matter caustics with weak lensing
The halo shape plays a central role in determining important observational properties of the haloes such as mass, concentration and lensing cross-sections. The triaxiality of lensing galaxy clusters has a substantial impact on the…
Full ray-tracing maps of gravitational lensing, constructed from N-Body simulations, represent a fundamental tool to interpret present and future weak lensing data. However the limitation of computational resources and storage capabilities…
Weak gravitational lensing seeks to determine shear by measuring induced quadrupole (elliptical) shapes in background galaxy images. Small impact parameter (a few kpc) gravitational lensing by foreground core masses between 2 10^{9} and 2…
Many independent high-resolution simulations of structure formation in cold dark matter models show that galactic halos should have singular core profiles. This is in stark contrast with observations of both low- and high-surface brightness…
We apply the linear filter for the weak-lensing signal of dark-matter halos developed in Maturi et al. (2005) to the cosmic-shear data extracted from the Garching-Bonn-Deep-Survey (GaBoDS). We wish to search for dark-matter halos through…
Two methods of constraining the properties of dark energy are weak lensing tomography and cluster counting. Uncertainties in mass calibration of clusters can be reduced by using the properties of halo clustering (the clustering of…
If dark matter interacts, even weakly, via non-gravitational forces, simulations predict that it will be preferentially scattered towards the trailing edge of the halo during collisions between galaxy clusters. This will temporarily create…
The continuous infall of dark matter with low velocity dispersion from all directions in a galactic halo leads to the formation of caustics which are very small scale ($\sim$parsec) high density structures. If the dark matter is made up of…
The total mass of clusters of galaxies is a key parameter to study massive halos. It relates to numerous gravitational and baryonic processes at play in the framework of large scale structure formation, thus rendering its determination…
Next-generation optical imaging surveys will revolutionise the observations of weak gravitational lensing by galaxy clusters and provide stringent constraints on growth of structure and cosmic acceleration. In these experiments, accurate…
Discrepancies have emerged between the predictions of standard cold dark matter (CDM) theory and observations of clustering on sub-galactic scales. Warm dark matter (WDM) is a simple modification of CDM in which the dark matter particles…
We demonstrate that the flux ratios of 4-image lensed quasars provide a powerful means of probing the small scale structure of Dark Matter (DM) halos. A family of smooth lens models can precisely predict certain combinations of flux ratios…
Recent studies have found that obscured quasars cluster more strongly and are thus hosted by dark matter haloes of larger mass than their unobscured counterparts. These results pose a challenge for the simplest unification models, in which…
It is known that the gravitational collapse of cold dark matter leads to infinite-density caustics that seed the primordial dark-matter halos in the large-scale structure. The development of these caustics begins, generically, as an almost…
Constraints on dark matter halo masses from weak gravitational lensing can be improved significantly by using additional information about the morphology of their density distribution, leading to tighter cosmological constraints derived…
Caustic-crossing stars observed in giant arcs behind galaxy clusters provide a powerful probe of dark matter substructure. While previous work has focused on point-like lenses such as primordial black holes, we extend this framework to…
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,…
Cosmological structure formation predicts that our galactic halo contains an enormous hierarchy of substructures and streams, the remnants of the merging hierarchy that began with tiny Earth mass microhalos. If these structures persist…
Cosmological models in which dark matter consists of cold elementary particles predict that the dark halo population should extend to masses many orders of magnitude below those at which galaxies can form. Here we report a cosmological…
The clustering of galaxies and their connections to their initial conditions is a major means by which we learn about cosmology. However, the stochasticity between galaxies and their underlying matter field is a major limitation for precise…