Related papers: Prospects for CDM sub-halo detection using high an…
Microlensing searches aim to detect compact halo dark matter via its gravitational lensing effect on stars within the Large Magellanic Cloud. The most recent results have led to the claim that roughly one fifth of the galactic halo dark…
The Cold Dark Matter (CDM) theory predicts a wealth of substructure within dark halos. These predictions match observations of galaxy clusters like the nearby Virgo cluster. However, CDM has a "small scale crisis" since galaxies dominate…
An important open question today is the understanding of the relevance that dark matter (DM) halo substructure may have for DM searches. In the standard cosmological framework, subhalos are predicted to be largely abundant inside larger…
A particular open problem in cosmology is whether dark matter on small scales is clumpy, forming gravitationally-bound halos distributed within the Galaxy. The practical difficulties inherent in testing this hypothesis stem from the fact…
Small distortions in the images of Einstein rings or giant arcs offer the exciting prospect of detecting dark matter haloes or subhaloes of mass below $10^9$M$_{\odot}$, most of which are too small to have made a visible galaxy. A very…
High resolution N-body simulations show that the density profiles of dark matter halos formed in the standard CDM cosmogony can be fit accurately by scaling a simple ``universal'' profile. Regardless of their mass, halos are nearly…
According to the Cold Dark Matter (CDM) hierarchical clustering theory of galaxy and large scale structure formation, there should be numerous low mass dark matter haloes present in the Universe today. If these haloes contain sufficient…
Luminous stars in background galaxies straddling the lensing caustic of a foreground galaxy cluster can be individually detected due to extreme magnification factors of $\sim 10^2$--$10^3$, as recently observed in deep HST images. We…
We use the semi-analytical approach to analyze gravitational lensing of quasars by dark halos in various cold dark matter (CDM) cosmologies, in order to determine the sensitivity of the prediction probabilities of images separations to the…
The dark matter halo of the Milky Way is predicted to contain a very large number of smaller subhalos. As a result of the dark matter annihilations taking place within such objects, the most nearby and massive subhalos could appear as…
In the cold dark matter (CDM) picture of structure formation, galaxy mass distributions are predicted to have a considerable amount of structure on small scales. Strong gravitational lensing has proven to be a useful tool for studying this…
We use N-body simulations to investigate the structure of dark halos in the standard Cold Dark Matter cosmogony. Halos are excised from simulations of cosmologically representative regions and are resimulated individually at high…
We analyse a high resolution simulation of the formation of a cluster's dark-matter halo in a $\Lambda$CDM cosmology (Springel et al. 2001). The resolution achieved allows us to map the phase-space structure in detail, and characterize its…
The mass assembly of a whole population of sub-Milky Way galaxies is studied by means of hydrodynamical simulations within the $\Lambda$-CDM cosmology. Our results show that while dark halos assemble hierarchically, in stellar mass this…
Simulations of dark matter show a discrepancy between the expected number of Galactic dark matter sub-halos and how many have been optically observed. Some of these unseen satellites may exist as dark dwarf galaxies: sub-halos like dwarf…
To set useful limits on the abundance of small-scale dark matter halos (subhalos) in a galaxy scale, we have carried out mid-infrared imaging and integral-field spectroscopy for a sample of quadruple lens systems showing anomalous flux…
We apply a semi-analytic galaxy formation model to two high resolution cosmological N-body simulations to investigate analogues of the Milky Way system. We select these according to observed properties of the Milky Way rather than by halo…
Dark matter-dominated cluster-scale halos act as an important cosmological probe and provide a key testing ground for structure formation theory. Focusing on their mass profiles, we have carried out (gravity-only) simulations of the…
A fundamental prediction of the cold dark matter cosmology is the existence of a large number of dark subhalos around galaxies, most of which should be entirely devoid of stars. Confirming the existence of dark substructures stands among…
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,…