Related papers: Need for context-aware computing in astrophysics

Considering the flat rotation curves as input and treating the matter content in the galactic halo region as quark matter, we have found out a background spacetime metric for the region of the galactic halo. We obtain fairly general…

The off-site continuums are proposed for the cosmological models of the galaxies and the Universe. It is shown that many visual properties of galaxies and the Universe may be described on frames of the off-site continuums methodology. In…

Massive neutrinos were the first proposed, and remain the most natural, particle candidate for the dark matter. In the absence of firm laboratory evidence for neutrino mass, considerations of the formation of large scale structure in the…

We suggest a new explanation of flatness of galaxies rotation curves without invoking dark matter. For this purpose a new gravitational tensor field is introduced in addition to the metric tensor.

The existence of dark matter in the Galactic disk has been a topic of significant debate, especially over the past two decades. Evidence for dark matter in the disk, a component in addition to the now well-proven dark matter halo, has been…

We present an analysis of a devised sample of Rotation Curves (RCs), aimed at checking the consequences of a modified f(R) gravity on galactic scales. Originally motivated by the the dark energy mystery, this theory may serve as a…

The Universal Rotation Curve (URC) of disk galaxies was originally proposed to predict the shape and amplitude of any rotation curve (RC) based solely on photometric data. Here, the URC is investigated with an extensive set of…

In a recent paper, published at arXiv:0910.2381, we started a discussion on the new possibilities arising from the use of fractional differential calculus in image processing. We have seen that the fractional calculation is able to enhance…

The aim of these notes is to elucidate some aspects of quantum field theory in curved spacetime, especially those relating to the notion of particles. A selection of issues relevant to wave-particle duality is given. The case of a generic…

Assuming the validity of the general relativistic description of gravitation on astrophysical and cosmological length scales, we analytically infer that the Friedmann-Robertson-Walker cosmology with Einsteinian cosmological constant, and a…

NASA has claimed the discovery of a `Ring of Dark Matter' in the galaxy cluster CL 0024+17, see Jee M.J. et al. arXiv:0705.2171, based upon gravitational lensing data. Here we show that the lensing can be given an alternative explanation…

Based on an exact solution of the Einstein field equations, it is proposed in this note that the dark-matter hypothesis could have led to the prediction of flat galactic rotation curves long before the discovery thereof by assuming that on…

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…

Cold dark matter (CDM) constitutes most of the matter in the Universe. The interplay between dark and luminous matter in dense cosmic environments like galaxy clusters is studied theoretically using cosmological simulations. Observed…

Dwarf galaxies represent a powerful probe of annihilating dark matter particle models, with gamma-ray data setting some of the best bounds available. A major issue in improving over existing constraints consists in the limited knowledge of…

We use the rotation curves of more than 100 disk galaxies to examine whether the structure of their surrounding dark halos is consistent with the universal density profile proposed by Navarro, Frenk & White (NFW profiles). Rotation curve…

The ubiquitous presence of dark matter in the universe is today a central tenet in modern cosmology and astrophysics. Ranging from the smallest galaxies to the observable universe, the evidence for dark matter is compelling in dwarfs,…

Over the past few decades, a consensus picture has emerged in which roughly a quarter of the universe consists of dark matter. I begin with a review of the observational evidence for the existence of dark matter: rotation curves of…

The light curve of an exoplanetary transit can be used to estimate the planetary radius and other parameters of interest. Because accurate parameter estimation is a non-analytic and computationally intensive problem, it is often useful to…

The simplest gauge gravitation theory in Riemann-Cartan space-time leading to the solution of the problem of cosmological singularity and dark energy problem is investigated with purpose to solve the dark matter problem. It is shown that…