Related papers: The thawing dark energy dynamics: Can we detect it…
The time evolution of the equation of state $w$ for quintessence models with a scalar field as dark energy is studied up to the third derivative ($d^3w/da^3$) with respect to the scale factor $a$, in order to predict the future observations…
In this paper we consider Tachyonic scalar field as dark energy with interaction between components in the case of variable $G$ and $\Lambda$. We assume a flat Universe with specific form of scale factor and study cosmological parameters…
In this paper we review in detail a number of approaches that have been adopted to try and explain the remarkable observation of our accelerating Universe. In particular we discuss the arguments for and recent progress made towards…
Early dark energy (EDE) models are a class of quintessence dark energy with a dynamically evolving scalar field which display a small but non-negligible amount of dark energy at the epoch of matter-radiation equality. Compared with a…
We present cosmological constraints arising from the first measurement of the radial (line-of-sight) baryon acoustic oscillations (BAO) scale in the large scale structure traced by the galaxy distribution. Here we use these radial BAO…
We study a dark energy scenario in the presence of a tachyon field $\phi$ with potential $V(\phi)$ and a barotropic perfect fluid. The cosmological dynamics crucially depends on the asymptotic behavior of the quantity…
K-essence is a minimally-coupled scalar field whose Lagrangian density $\mathcal{L}$ is a function of the field value $\phi$ and the kinetic energy $X=\frac{1}{2}\partial_\mu\phi\partial^\mu\phi$. In the thawing scenario, the scalar field…
Cosmological observations of the recent universe suggest that dark energy equation of state parameter $w$ is growing with time, departing from a cosmological constant for which $w=-1$. Standard quintessence models allow for a varying…
A light scalar field framework of dark energy, sometimes referred to as quintessence, introduces a fifth force between normal matter objects. Screening mechanisms, such as the chameleon model, allow the scalar field to be almost massless on…
Mapping the behaviour of dark energy is a pressing task for observational cosmology. Phenomenological classification divides dynamical dark energy models into freezing and thawing, depending on whether the dark energy equation of state is…
Oscillating scalar fields, with an oscillation frequency much greater than the expansion rate, have been proposed as models for dark energy. We examine these models, with particular emphasis on the evolution of the ratio of the oscillation…
We investigate in this paper the cosmological evolution of a dark energy model with two scalar fields where one of the scalar has canonical kinetic energy and another scalar has negative kinetic energy term. For such a system with…
The observational effect of all minimally coupled scalar field models of dark energy can be determined by the behavior of the following two parameters : (1) equation of state parameter $w$, which relates dark energy pressure to its energy…
The current Universe is composed by a mixture of relativistic species, baryonic matter, dark matter and dark energy which evolve in a non-trivial way at perturbative level. An advanced description of the cosmological dynamics should include…
We consider the generic scenario of dark energy which arises through the latent heat of a hidden sector first order cosmological phase transition. This field could account for the extra radiation degree of freedom suggested by the CMB. We…
We study the holographic dark energy model in a generalized scalar tensor theory. In a universe filled with cold dark matter and dark energy, the effect of potential of the scalar field is investigated in the equation of state parameter. We…
In this work we perform some studies related to dark energy. Firstly, we propose a dynamical approach to explain the dark energy content of the universe. We assume that a massless scalar field couples to the Hubble parameter with some…
In the present work we study a dark energy model in which a non-linear scalar field (tachyon) with a Born-Infeld type of action is responsible for the observed cosmic acceleration. The potential of the tachyon is well-motivated since it…
We use observational data from Type Ia Supernovae (SN), Baryon Acoustic Oscillations (BAO), Cosmic Microwave Background (CMB) and observational Hubble data (OHD), and the Markov Chain Monte Carlo (MCMC) method, to constrain the cosmological…
Dark energy away from a cosmological constant $\Lambda$ -- like early universe inflation that ends -- can be understood in terms of well defined physical behaviors. These guide dark energy into thawing or freezing classes, with $w_0$--$w_a$…