相关论文: Probing dark matter caustics with weak lensing
Caustics are formally singular structures, with infinite density, that form in collisionless media. The non-negligible velocity dispersion of dark matter particles renders their density finite. We evaluate the maximum density of the…
Dark matter caustics have specific density profiles and, therefore, precisely calculable gravitational lensing properties. We present a formalism which simplifies the relevant calculations, and apply it to four specific cases. In the first…
We show that most particle and subhalo orbits in simulated cosmological cold dark matter halos are surprisingly regular and periodic: The phase space structure of the outer halo regions shares some of the properties of the classical…
Cold dark matter haloes are populated by high-density structures with sharply-peaked profiles known as caustics which have not yet been resolved by 3-dimensional numerical simulations. Here, we derive semi-analytic expressions for the…
We simulate the growth of isolated dark matter haloes from self-similar and spherically symmetric initial conditions. Our N-body code integrates the geodesic deviation equation in order to track the streams and caustics associated with…
Dark matter density is formally infinite at the location of caustic surfaces, where dark matter sheet folds in phase space. The caustics separate multi-stream regions with different number of streams. Volume elements change the parity by…
Cold dark matter haloes are populated by caustics, which are yet to be resolved in N-body simulations or observed in the Universe. Secondary infall model provides a paradigm for the study of caustics in "typical" haloes assuming that they…
The late infall of cold dark matter onto an isolated galaxy such as our own produces flows with definite velocity vectors at any physical point in the galactic halo. It also produces caustics which are places where the dark matter density…
Gravitational collapse of dark matter, merger of dark matter haloes and tidal disruption of satellites are among processes which lead to the formation of fine and dense dark matter shells, also known as dark matter caustics. The putative…
We examine scatter and bias in weak lensing selected clusters, employing both an analytic model of dark matter haloes and numerical mock data of weak lensing cluster surveys. We pay special attention to effects of the diversity of dark…
The possibility that stellar mass primordial black holes may make up at least a significant fraction of dark matter has recently received much attention, partly as a result of gravitational wave observations, but more specifically from…
I elaborate on my prediction that an indirect detection of cold dark matter (CDM) may be possible by observing the gravitational lensing effects of the CDM cusp caustics at cosmological distances. Cusps in the distribution of CDM are…
We study the gravitational lensing properties of a massive object in a dark matter halo, concentrating on the critical curves and caustics of the combined lens. We model the system in the simplest approximation by a point mass embedded in a…
The hierarchical cold dark matter (CDM) model for structure formation is a well defined and testable model. Direct detection is the best technique for confirming the model yet predictions for the energy and density distribution of particles…
There are compelling reasons to believe that the dark matter of the universe is constituted, in large part, by non-baryonic collisionless particles with very small primordial velocity dispersion. Such particles are called cold dark matter…
Although a simple argument implies that the distribution of dark matter in galactic halos is characterized by discrete flows and caustics, their presence is often ignored in discussions of galactic dynamics and of dark matter detection…
We explore a variety of statistics of clusters selected with cosmic shear measurement by utilizing both analytic models and large numerical simulations. We first develop a halo model to predict the abundance and the clustering of weak…
The distortion of the images of faint high-redshift galaxies can be used to probe the intervening mass distribution. This weak gravitational lensing effect has been used recently to study the (projected) mass distribution of several…
Caustics are a generic feature of the nonlinear growth of structure in the dark matter distribution. If the dark matter were absolutely cold, its mass density would diverge at caustics, and the integrated annihilation probability would also…
For nearly 40 years, dark matter has been widely assumed to be cold and collisionless. Cold dark matter models make fundamental predictions for the behavior of dark matter on small (<10 kpc) scales. These predictions include cuspy density…