In this paper we are interested to consider mathematical ways to obtain different phenomenological fluids from two-component Tachyonic scalar fields. We consider interaction between components and investigate problem numerically. Statefinder diagnostics and validity of the generalized second law of thermodynamics performed and checked. We suppose that our Universe bounded by Hubble horizon.

In this paper, we consider three different models of dark energy in higher dimensional space-time and discuss about some cosmological parameters numerically. The first model is a single component universe including viscous varying modified Chaplygin gas. In the second model, we consider two-component universe including viscous varying modified Chaplygin gas and ghost dark energy. In the third model, we consider another two-component universe including viscous modified cosmic Chaplygin gas and ghost dark energy. In the cases of two-component fluids we also consider possibility of interaction between components.

In this paper we make steps in a new direction by considering fluids with EoS of more general form F (ρ, P ) = 0. It is thought that there should be interaction between cosmic fluids, but this assumption for this stage carries only phenomenological character opening a room for different kind of manipulations. In this article we will consider a modification of an interaction Q, where we accept that interaction parameter b 1 (order of unity) in Q = 3Hb 1 ρ is time dependent and presented as a linear function of Hubble parameter H of the form b 0 + btH, where b and b 0 are constants. We consider two different models include modified Chaplygin gas and palotropic gas which have bulk viscosity. Then, we investigate problem numerically and analyze behavior of different cosmological parameters concerning to fluids and behavior of Universe. *

In this paper, we consider Tachyonic scalar field as a model of dark energy with interaction between components in the case of variable G and Λ. We assume a flat Universe with specific form of scale factor and study cosmological parameters numerically and graphically. Statefinder analysis also performed as well. In the special choice of interaction parameters we succeed to obtain analytical expression of densities. We find that our model will be stable in the late stage but there is an instability at the early Universe. So we propose this model as a realist model of our Universe.

In this work, we studied the Power Law and the Logarithmic Entropy Corrected versions of the Ricci Dark Energy (RDE) model in a spatially non-flat universe and in the framework of Hořava-Lifshitz cosmology. For the two cases containing non-interacting and interacting RDE and Dark Matter (DM), we obtained the exact differential equation that determines the evolutionary form of the RDE energy density parameter. Moreover, we obtained the expressions of the deceleration parameter q and, using a parametrization of the equation of state (EoS) parameter ω D as ω D (z) = ω 0 + ω 1 z, we derived the expressions of both ω 0 and ω 1 . We interestingly found that the expression of ω 0 is the same for both non-interacting and interacting case. The expression of ω 1 for the interacting case has strong dependence from the interacting parameter b 2 . The parameters derived in this work are done in small redshift approximation and for low redshift expansion of the EoS parameter. * Electronic address: toto.pasqua@gmail.com; Electronic address: surajcha@iucaa.ernet.in; Electronic ad-2

In this paper we will demonstrate possible existence of more exotic forms of interaction taking into account, that dark energy can be parametrized as a varying polytropic fluid suggested recently by the first author. On going research in both directions, i.e. dark energy and non-gravitational interaction, opens very interesting perspectives for solving the problems which are related to the accelerated expansion of the Universe. The fact that available observational data allows to parametrize the dark side of our Universe in form of interacting dark fluids is not less surprising, than the accelerated expansion itself. Therefore, the consideration of new forms of non-gravitational interactions in modern cosmology still is one of the actual topics and requires deep and systematic research. This fact motivates us to consider various new forms of non-gravitational logarithmic interactions and study their cosmological consequences. Appropriate classification of the models is presented in the light of actively discussed Om analysis and the result for the Hubble parameter measured at z = 2.34 in BOSS experiment. *

A model of the asymmetric coherent scattering process (caused by initial atomic wave-packet splitting in the momentum space) taking place at the large detuning and adiabatic course of interaction for an effective two-state system interacting with a standing wave of laser radiation is discussed. We show that the same form of initial wave-packet splitting may lead to different, in general, diffraction patterns for opposite, adiabatic and resonant, regimes of the standing-wave scattering. We show that the scattering of the Gaussian wave packet in the adiabatic case presents refraction (a limiting form of the asymmetric scattering) in contrast to the bi-refringence (the limiting case of the high-order narrowed scattering) occurring in the resonant scattering. [20]. These efforts have led to advanced representations on the scattering of atoms by standing waves extending the diversity of the scenarios of interference occurring during the interaction of atoms with the field of optical lattices and, in general, mechanical action of light on the matter waves [21]- [25].The asymmetric scattering model employs secondary quantum-mechanical interference during interaction with the radiation field to achieve different intended target states. This interference is due to superposition initial states. It has been shown that the preparation of particles prior to interaction in specific (in general, optomechanically mixed) states is able to dramatically alter the interaction pattern [3]- [4]. A basic example of such a change is the strong asymmetry in the scattering pattern in the case when the atomic wave packet is initially split into two momentum peaks differing by an odd number of photon momenta [4]. Even more advanced are the various elaborate initial superposition states [3]-[8] that may result in a large amplitude coherent accumulation of the momentum on the internal energy levels caused by: single photon exchange [5], narrowing of the interference fringes of the diffraction pattern [7], standing-wave refraction of atoms with initial Gaussian distribution of amplitudes by momenta [11], etc. These effects suggest more flexibility in the control of atomic motion and hence can be useful in atom optics, in particular, in atom interferometric and atom nanolithographic applications (see, e.g., [26]).The peculiarities of asymmetric scattering are expressed further when dealing with the close neighborhood of exact resonance or when the fast switching on/off of a laser pulse is involved in the process. This is because, in these cases, stronger excitation of the system is achieved. Besides, the sudden inclusion of the interaction, an essentially non-adiabatic process, suggests more flexibility in choosing different preparation states. However, it is understood that many of the explored effects can also be observed in the adiabatic regime, i.e. at large detunings of the wave frequency and the slow course of the interaction. Since the adiabatic interaction schemes as a rule suggest more robust technologies, complementary discussions o...