Related papers: Fitting the Galaxy Rotation Curves: Strings versus…
The approximately flat outer parts of spiral galaxy rotation curves are commonly interpreted as evidence for a discrepancy between the observed baryonic mass and the dynamical mass inferred from the measured orbital velocities. In many…
Higher order curvature gravity has recently received a lot of attention due to the fact that it gives rise to cosmological models which seem capable of solving dark energy and quintessence issues without using "ad hoc" scalar fields. In…
Recent measurements of gas velocity in the outer parts of high redshift galaxies suggest that steeply falling rotation curves may be common, or even universal, in these galaxies, in contrast to the near universal flat, non-declining…
Double Field Theory suggests to view the whole massless sector of closed strings as the gravitational unity. The fundamental symmetries therein, including the $\mathbf{O}(D,D)$ covariance, can determine unambiguously how the Standard Model…
We present a simple technique to estimate mass-to-light (M/L) ratios of stellar populations based on two broadband photometry measurements, i.e. a color-M/L relation. We apply the color-M/L relation to galaxy rotation curves, using a large…
In cosmological N-body simulations, the baryon effects on the cold dark matter (CDM) halos can be used to solve the small scale problems in $\Lambda$CDM cosmology, such as cusp-core problem and missing satellites problem. It turns out that…
Rotation curves of galaxies probe their total mass distributions, including dark matter. Dwarf galaxies are excellent systems to investigate the dark matter density distribution, as they tend to have larger fractions of dark matter compared…
Ingoing and outgoing principal null geodesics in Kerr spacetimes are characterized as part of parametrized families of strings in complex Kerr geometry and are associated with holomorphic curves in twistor space with help of the Kerr…
Conformal gravity theory can explain observed flat rotation curves of galaxies without invoking hypothetical dark matter. Within this theory, we obtain a generic formula for the sizes of galaxies exploiting the stability criterion of…
The standard cold dark matter (CDM) model has recently been challenged by the claim that dwarf galaxies have dark matter halos with constant density cores. Consequently, numerous alternative dark matter candidates have recently been…
We present the analysis of 12 high-resolution galactic rotation curves from The HI Nearby Galaxy Survey (THINGS) in the context of modified Newtonian dynamics (MOND). These rotation curves were selected to be the most reliable for mass…
We show that in a wide class of string derived models of particle physics, heavy string modes with masses around the GUT scale can serve as a viable dark matter candidate. These heavy string modes wind around specific cycles in the…
Density profiles of simulated galaxy cluster-sized dark matter haloes are analysed in the context of a recently introduced nonextensive theory of dark matter and gas density distributions. Nonextensive statistics accounts for long-range…
Using a large set of ray-tracing in N-body simulations, we examine lensing profiles around massive dark haloes in detail, with a particular emphasis on the profile at around the virial radii. We compare radial convergence profiles, which…
In the background of $f(R, L_m)$ gravity, this work investigates three distinct dark matter halo profiles to test the possibility of generalised wormhole geometry within the galactic halo regions. The current study aims to accomplish these…
Feng & Gallo (2011) developed a numerical method of deriving rotation curves from the density distribution and, in particular, the inverse problem while considering just a self-gravitating disc and the thin disc approximation. Our first aim…
The simplest scheme for predicting real galaxy properties after performing a dark matter simulation is to rank order the real systems by stellar mass and the simulated systems by halo mass and then simply assume monotonicity - that the more…
Using the standard dynamical theory of spherical systems, we calculate the properties of spherical galaxies and clusters whose density profiles obey the universal form first obtained in high resolution cosmological N-body simulations by…
We argued that the standard field scalar potential couldn't be widely used for getting the adequate galaxies' curve lines and determining the profiles of dark matter their halo. For discovering the global properties of scalar fields that…
The cosmic string scenario in an open universe is developed -- including the equations of motion, a model of network evolution, the large angular scale CMB temperature anisotropy, and the power spectrum of density fluctuations produced by…