Related papers: Dark Matter, Dark Energy and Rotation Curves
The spacetime satisfying the flat curve condition for galaxies is shown to be the zero mass limit of the dilaton blackhole with an exponential potential. We derive the geodesic equations and by studying rotational curves and light…
Recent Strong lensing data and rotation curves of dwarf galaxies indicate that many galactic clusters may have a soft core instead of a central cusp in their density distribution. This result challenges the standard CDM (Cold Dark Matter)…
We consider the consequences of applying general relativity to the description of the dynamics of a galaxy, given the observed flattened rotation curves. The galaxy is modeled as a stationary axially symmetric pressure-free fluid. In spite…
We investigate the spatial properties of the large scale structure (LSS) of the Universe in the framework of coupled dark energy (cDE) cosmologies. Using the public halo catalogues from the CoDECS simulations -- the largest set of N-body…
We investigate whether a dark matter with substantial amounts of pressure, comparable in magnitude to the energy density, could be a viable candidate for the constituent of dark matter halos. We find that galaxy halos models, consistent…
We investigate the spacetime of a slowly rotating black hole in the Chern-Simons modified gravity. The long range feature of frame-dragging effect under the Chern-Simon gravity well explains the flat rotation curves of galaxies which is a…
Recent results from gravitational lensing are combined with new modeling of the stellar velocity distributions in nearby galaxies to probe the connection between the luminous and the dark matter in elliptical galaxies. From analysing a…
A new method is developed which permits the reconstruction of the surface-density distribution in the galactic disk of finite radius from an arbitrary smooth distribution of the angular velocity via two simple quadratures. The existence of…
A Born-Infeld theory has been proposed in order to explain both dark matter and dark energy. We show that the approximation used to deduce the flat rotation curves in this model breaks down at large distances in a spherically symmetric…
We present mass models for the dark matter component of seven dwarf galaxies taken from "The HI Nearby Galaxy Survey" (THINGS) and compare these with those from numerical Lambda Cold Dark Matter (LCDM) simulations. The THINGS…
Clusters of galaxies, being dark matter dominated, have long been and still are the ideal cosmological targets to study the nature of dark matter. Constraints on the nature of dark matter comes in particular from the observational…
We study properties of dark matter halos in a variety of models which include Dark Energy (DE). We consider both DE due to a scalar field self--interacting through Ratra-Peebles or SUGRA potentials, and DE with constant negative w=p\rho…
Clusters of galaxies are studied from a theoretical point of view, comparing with observational results whenever possible. The problem is approached both analytically as well as by means of high-resoultion numerical simulations. The dark…
Deep observations of galaxy outskirts reveal faint extended stellar components (ESCs) of streams, shells, and halos, which are ghostly remnants of the tidal disruption of satellite galaxies. We use cosmological galaxy formation simulations…
Matter and dark matter in galaxies represent two main components linked by the gravitational interaction. Collisions of galaxies may create an offset between the centers of mass of these components. Ignoring internal dynamics of particles…
The quest for the elusive dark matter (DM) that permeates the Universe (and in general the search for signatures of Physics beyond the Standard Model at astronomical scales) provides a unique opportunity and a tough challenge to the…
Modified dark matter (MDM, formerly known as MoNDian dark matter) is a phenomenological model of dark matter, inspired by quantum gravity. We review the construction of MDM by generalizing entropic gravity to de-Sitter space as is…
A recent study using weak gravitational lensing reveals that there are some isolated galaxies having almost flat rotation curves at very large distance from the galactic centres. According to the authors of the study this provides a strong…
The propagation of weak gravitational waves on the background of dark energy is studied. The consideration is carried out within the framework of an approximate approach where the cosmological scale factor is expanded as a power series for…
We consider the singular configurations of gravitating gas [1] which could be used as a model for disk galaxies. The simplest steady configuration, which corresponds to rotation of stars around center gives flat rotational curve, provided…