Related papers: Evolution of velocity dispersion along cold collis…
We perform a statistical analysis of the peculiar velocity field around dark matter haloes in numerical simulations. We examine different properties of the infall of material onto haloes and its relation to central halo shapes and the shape…
Small-scale challenges to $\Lambda$CDM cosmology require a deeper understanding of dark matter physics.This paper aims to develop maximum entropy distributions for dark matter particle velocity (denoted by $X$), speed (denoted by $Z$), and…
When a dark matter halo moves through a background of dark matter particles, self-interactions can lead to both deceleration and evaporation of the halo and thus shift its centroid relative to the collisionless stars and galaxies. We study…
Using $N$-body simulations ($N\sim 10^6 - 10^7$), we examine how a non-axisymmetric dark halo affects the dynamical evolution of the structure in collisionless (stellar) discs. We demonstrate how the model parameters such as mass of the…
Intrinsically cold particle dark matter inevitably creates halos with sharp discontinuities in projected surface density caused by the projection of fold catastrophes onto the sky. In principle, these imperfections can be detected and…
N-body simulations and analytical calculations of the gravitational collapse in an expanding universe predict that halos should form with a diverging inner density profile, the cusp. There are some observational indications that the dark…
We study the velocities of the accretion along streams from the cosmic web into massive galaxies at high redshift with the help of three different suites of AMR hydrodynamical cosmological simulations. The results are compared to free-fall…
The root-mean-square of non-relativistic warm dark matter particle velocities scales as $v_{h\textrm{rms}}(a) = v_{h\textrm{rms}}(1)/a$, where $a$ is the expansion parameter of the universe. This velocity dispersion results in a cut-off of…
Many scaling relations are observed for self-gravitating systems in the universe. We explore the consistent understanding of them from a simple principle based on the proposal that the collision-less dark matter fluid terns into a turbulent…
With the success of the Chandra and XMM missions and the maturation of gravitational lensing techniques, powerful constraints on the orbital structure of cluster dark matter halos are possible. I show that the X-ray emissivity and mass of a…
We present Keck/OSIRIS adaptive optics observations with 150-400 pc spatial sampling of 7 turbulent, clumpy disc galaxies from the DYNAMO sample ($0.07<z<0.2$). DYNAMO galaxies have previously been shown to be well matched in properties to…
Dark matter self-interactions may have the capability to solve or at least mitigate small-scale problems of the cosmological standard model, Lambda Cold Dark Matter. There are a variety of self-interacting dark matter models that lead to…
We present large-scale molecular dynamics simulations to study the free evolution of granular gases. Initially, the density of particles is homogeneous and the velocity follows a Maxwell-Boltzmann (MB) distribution. The system cools down…
Within the disk model framework used to approximately describe flattened galaxies, we develop an iterative method of determining column mass density from rotation curve supplemented with isotropic velocity dispersion profile. This…
An analysis of large-area CO J=3-2 maps from the James Clerk Maxwell Telescope for 12 nearby spiral galaxies reveals low velocity dispersions in the molecular component of the interstellar medium. The three lowest luminosity galaxies show a…
The redshift and size distributions of galaxy scale strong lenses depend on the evolution of early-type galaxies (ETGs). We use this dependence to constrain the velocity dispersion function (VDF) evolution from the Strong Lensing Legacy…
We discuss the process of adiabatic growth of central black holes in the presence of a stationary, pre-existing distribution of collisionless stars. Within the limitations of the assumptions, the resulting models make robust physical…
We perform a statistical study of the global motion of cosmic voids using both a numerical simulation and observational data. We analyse their relation to large-scale mass flows and the physical effects that drive those motions. We analyse…
We study the distribution of dark matter in dwarf spheroidal galaxies by modelling the moments of their line-of-sight velocity distributions. We discuss different dark matter density profiles, both cuspy and possessing flat density cores.…
We present new velocity dispersion measurements of sample of 12 spiral galaxies for which extended rotation curves are available. These data are used to refine a recently discovered correlation between the circular velocity and the central…