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Open Physics
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2011
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vol. 9
|
issue 3
628-643
EN
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 matter can only be unraveled by its direct detection in the laboratory. In this work we present some theoretical elements relevant to the direct dark matter detection experiments, paying particular attention to directional experiments, i.e. experiments in which not only the energy but the direction of the recoiling nucleus is observed. Since the direction of observation is fixed with respect to the Earth, while the Earth is rotating around its axis, in a directional experiment the angle between the direction of observation and the Sun’s direction of motion will change during the day. So, since the event rates sensitively depend on this angle, the observed signal in such experiments will exhibit very interesting and characteristic periodic diurnal variation.
2
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Dark ingredients in one drop

100%
Open Physics
|
2011
|
vol. 9
|
issue 3
644-653
EN
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 represents distributed vacuum dark energy by a time-evolving and spatially inhomogeneous cosmological term, and vacuum dark matter by gravitational vacuum solitons which are regular gravitationally bound structures without horizons (dark particles or dark stars), with the de Sitter centre (Λδki) in de Sitter space (λδki).
Open Physics
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2010
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vol. 8
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issue 5
771-781
EN
Based on a possible solution to the tetron spin problem, a modification of the standard Big Bang scenario is suggested, where the advent of a space-time manifold is connected to the appearance of tetronic bound states. The metric tensor is constructed from tetron constituents and the reason for cosmic inflation is elucidated. Furthermore, there are natural dark matter candidates in the tetron model. The ratio of ordinary to dark matter in the universe is calculated to be 1:5.
4
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AdS braneworld with backreaction

80%
Open Physics
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2014
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vol. 12
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issue 3
147-159
EN
We review the tachyon model derived from the dynamics of a 3-brane moving in the AdS5 bulk. The bulk geometry is based on the Randall-Sundrum II model extended to include the radion. The effective tachyon Lagrangian is modified due to the back-reaction of the brane on the bulk geometry.
5
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Classical color fields as a dark matter candidate

80%
Open Physics
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2007
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vol. 5
|
issue 3
342-350
EN
A model of Dark Matter is proposed where the Dark Matter is a classical color field. The color fields are invisible as they may interact with colored elementary particles like the ’t Hooft-Polyakov monopole only. Comparison with the Universal Rotation Curve is carried out.
6
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On the gravitodynamics of moving bodies

51%
Open Physics
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2011
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vol. 9
|
issue 5
1151-1164
EN
In the present work we propose a generalization of Newton’s gravitational theory from the original works of Heaviside and Sciama, that takes into account both approaches, and accomplishes the same result in a simpler way than the standard cosmological approach. The established formulation describes the local gravitational field related to the observables and effectively implements the Mach’s principle in a quantitative form that retakes Dirac’s large number hypothesis. As a consequence of the equivalence principle and the application of this formulation to the observable universe, we obtain, as an immediate result, a value of Ω = 2. We construct a dynamic model for a galaxy without dark matter, which fits well with recent observational data, in terms of a variable effective inertial mass that reflects the present dynamic state of the universe and that replicates from first principles, the phenomenology proposed in MOND. The remarkable aspect of these results is the connection of the effect dubbed dark matter with the dark energy field, which makes it possible for us to interpret it as longitudinal gravitational waves.
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