No abstract

We propose in this paper an interacting holographic dark energy (IHDE) model in chameleontachyon cosmology by interaction between the components of the dark sectors. In the formalism, the interaction term emerges from the scalar field coupling matter lagrangian in the model rather than being inserted into the formalism as an external source for the interaction. The correspondence between the tachyon field and the holographic dark energy (HDE) densities allows to reconstruct the tachyon scalar field and its potential in a flat FRW universe. The model can show the accelerated expansion of the universe and satisfies the observational data. * Electronic address: hosseinf@guilan.ac.ir † Electronic address: aravanpak@guilan.ac.ir ‡ Electronic address: gfadakar@guilan.ac.ir 1

In this article we study an intermediate inflationary model in the context of Dvali-GabadadzePorrati (DGP) cosmology caused by a tachyon scalar field. Considering slow-roll inflation we discuss the dynamics of the Universe. Using perturbation theory, we estimate some of the model parameters numerically and compare them with the recent results from Planck satellite.

In this article we study cosmic dynamics in the context of normal branch of DGP braneworld model. Using the current Planck data, we best fit the model and cosmological parameters in nonflat ΛDGP. With the transition redshift as a basic variable and statefinder parameters, our result shows that the Universe starts its accelerated expansion phase, slightly earlier than expected in ΛCDM cosmology. The result also alleviates the coincidence problem of the ΛCDM model.

In this manuscript we use the dynamical system approach to study the linear dynamics of a normal DGP brane-world model with a tachyon field as the dark energy component. Our focus is on a Gaussian tachyonic potential in which the parameter λ = −V φ /V 3/2 , goes to infinity. One of the most important results of this study is that we find critical submanifolds which indicate the effect of extra dimension. Also, we find that in this model the universe will experience another transition from acceleration to deceleration in the future.