Related papers: Evolution of Phase-Space Density in Dark Matter Ha…
A method is presented for computing the 6-D phase-space density f(x,v) and its PDF v(f) in an N-body system. It is based on Delaunay tessellation, yielding v(f) with a fixed smoothing window over a wide f range, independent of the sampling…
Properties of dark matter halos are reviewed. Taken from different publications, we present results on (1) the mass and velocity functions, (2) density and velocity profiles, and (3) concentration of halos. In the range of radii…
This paper presents a study of the specific merger rate as a function of group membership, local environment, and redshift in a very large, $500h^{-1} Mpc$, cosmological N-body simulation, the \textit{Millennium Simulation}. The goal is to…
Numerous observations have shown that almost all galaxies in our Universe host supermassive black holes (SMBHs), but there is still much debate about their formation and evolutionary processes. Recently, gravitational waves (GWs) have been…
On the basis of a new convergence study of high-resolution N-body simulations, my colleagues and I now agree that the Navarro, Frenk, & White (1996) density profile $\rho_{NFW}(r) \propto r^{-1} (r+r_s)^{-2}$ is a good representation of…
In the hierarchical structure formation model cosmic halos are supposed to form by accretion of smaller units along anisotropic direction, defined by large-scale filamentary structures. After the epoch of primary mass aggregation (which…
Without relying on a spherical or ellipsoidal collapse model, we analytically derive the halo mass function and cuspy halo density (inner slope of -4/3) based on the mass and energy cascade theory in dark matter flow. The hierarchical halo…
We conducted an analysis on dark matter halo properties following major and minor mergers to advance our understanding of halo evolution. In this work, we analyzed ~80,000 dark matter halos from the Bolshoi-Planck cosmological simulation…
We study properties of dark matter halos at high redshifts z=2-10 for a vast range of masses with the emphasis on dwarf halos with masses 10^7-10^9 Msun/h. We find that the density profiles of relaxed dwarf halos are well fitted by the NFW…
In this paper, we study the dynamical stability and time evolution of the central dark matter cores of low-mass (about 10^8-10^9 M_solar) galactic haloes found in recent cold dark matter simulations at high redshift. From those simulations…
We investigate dark matter halo properties as a function of a time--varying dark energy equation of state. The dynamics of the collapse of the halo is governed by the form of the quintessence potential, the time evolution of its equation of…
We present a method for computing the 6-dimensional coarse-grained phase-space density $f(x,v)$ in an N-body system, and derive its distribution function $v(f)$. The method is based on Delaunay tessellation, where $v(f)$ is obtained with an…
The Cold Dark Matter paradigm successfully explains many phenomena on scales larger than galaxies, but seems to predict galaxy halos which are more centrally concentrated and have a lumpier substructure than observed. Endowing cosmic dark…
A novel analytical Schwarzschild-like black hole (BH) solution is derived. It exhibits a static BH with a dark matter (DM) halo characterized by a Dehnen-type density profile. This solution could represent an alternative perspective on the…
N-body simulations of dark matter halos show that the density is cusped near the center of the halo. The density profile behaves as $r^{-\gamma}$ in the inner parts, where $\gamma \simeq 1$ for the NFW model and $\gamma \simeq 1.5$ for the…
Several lines of evidence suggest that as dark matter haloes grow their scale radius increases, and that the density in their central region drops. Major mergers seem an obvious mechanism to explain both these phenomena, and the resulting…
I use $N$-body simulations to investigate the morphology and the dynamical evolution and properties of dark matter halos in clusters of galaxies. My sample consists of nine massive halos, coming from an Einstein-de Sitter universe with…
We examine the bar instability in galactic models with an exponential disk and a cuspy dark matter (DM) halo with a Navarro-Frenk-White (NFW) cosmological density profile. We construct equilibrium models from a 3-integral composite…
We study the formation and evolution of self-interacting dark matter (SIDM) halos. We find analytical, fully cosmological similarity solutions taking account of the collisional interaction of SIDM particles. This interaction results in a…
Dark matter (DM) halos simulated via N-body techniques are known to exhibit nearly universal profiles at equilibrium; however, their origin remains uncertain despite thorough investigation. This work aims to probe the origin of simulated DM…