Published in Open Astronomy
The SDSS galaxy catalog is one of the best databases for galaxy distribution studies. The SDSS DR8 data is used to construct the galaxy cluster catalog. We construct the clusters from the calculated luminosity density field and identify denser regions. Around these peak regions we construct galaxy clusters. Another interesting question in cosmology...
Published in Open Astronomy
Applying the formulae derived by us (A. Sapar 1964) for the Universe filled with baryonic matter and decoupled particles (photons and massive neutrinos), a scenario of evolution of the Universe is studied. The dark energy can be treated as the kinetic energy excess over the potential energy of all particles in the hyperbolic Universe which is going...
Published in Science China Physics, Mechanics and Astronomy
A naive toy model that the fermion sea offers the dark matter density is discussed here. If the fermion sea fills the total space and the temperature equals the temperature of CMB, we can get the mass of the fermion is about 4.7 × 10−38 kg (0.026 eV).
The Modified Newtonian Dynamics (MOND) has been formulated as a modification of the Poisson equation for the Newtonian gravitational field. This theory generically predicts a violation of the strong version of the equivalence principle, and as a result the gravitational dynamics of a system depends on the external gravitational field in which the s...
In this paper, we study the distribution functions that arise naturally during self-similar radial infall of collisionless matter. Such matter may be thought of either as stars or as dark matter particles. If a rigorous steady state is assumed, then the system is infinite and is described by a universal distribution function given the self-similar ...
Published in Russian Physics Journal
A spatially flat Friedmann universe filled with two interacting ideal fluids (dark energy and dark matter) is considered. The gravitational equations of motion are solved with allowance for the interaction between dark energy and dark matter. It is shown that a periodic universe can form with cosmological singularities, it becomes static in the inf...
Published in Astronomy Letters
The possibility of using a trap with ultracold neutrons as a detector of dark matter particles with long-range forces is considered. The main advantage of the proposed method lies in the possibility of detecting a recoil energy of ∼10−7 eV. Constraints on the parameters of an interaction potential of the form φ (r) = ae−r/b/r between dark matter pa...
Published in Open Physics
A unified description of dark ingredients is realized by a vacuum dark fluid defined by symmetry of its stress-energy tensor and allowed by General Relativity. The symmetry is reduced compared with the maximally symmetric de Sitter vacuum, which makes vacuum dark fluid essentially anisotropic and allows its density and pressure to evolve. It repres...
Published in Open Physics
The recent WMAP data have confirmed that exotic dark matter together with the vacuum energy (cosmological constant) dominate in the flat Universe. Modern particle theories provide viable cold dark matter candidates with masses in the GeV-TeV region. All such candidates will be called WIMPs (Weakly Interacting Massive Particles). The nature of dark ...
In experiments looking for rare events, like neutrinoless double beta decay (DBD0v) and dark matter search (DM), one of the main issues is to increase the experimental sensitivity through the material selection and production. In the specific the background contribution coming from the materials used for the detector realization has to be minimized...
