Related papers: Twinlike models for parametrized dark energy
In this paper we study the possibility of building models of dark energy with equation of state across -1 and propose explicitly a model with a single scalar field which gives rise to an equation of state larger than -1 in the past and less…
A two-component fluid representing dark energy is studied. One of the components has a polytropic form, while the other has a barotropic form. Exact solutions are obtained and the cosmological parameters are constrained using supernova type…
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…
The dynamical properties of a model of dark energy in which two scalar fields are coupled by a non-canonical kinetic term are studied. We show that overall the addition of the coupling has only minor effects on the dynamics of the two-field…
One possible description for the current accelerated expansion of the universe is quintessence dynamics. The basic idea of quintessence consists of analyzing cosmological scenarios driven by scalar fields. In this work we present some…
We explore the recently introduced statefinder parameters. After reviewing their basic properties, we calculate the statefinder parameters for a variety of cosmological models, and investigate their usefulness as a means of theoretical…
The dark energy cosmology with the equation of state $w=constant$ is considered in this paper. The $\Omega_{DE}-\Omega_{M}$ plane has been used to study the present state and expansion history of the universe. Through the mathematical…
Some functions entering cosmological analysis, such as the dark energy equation of state or systematic uncertainties, are unknown functions of redshift. To include them without assuming a particular form we derive an efficient method for…
Dark Energy models are numerous and distinguishing between them is becoming difficult. However, using distinct observational probes can ease this quest and gives better assessment to the nature of Dark energy. To this end, the plausibility…
Observational evidence indicating that the expansion of the universe is accelerating has surprised cosmologists in recent years. Cosmological models have sought to explain this acceleration by incorporating `dark energy', of which the…
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…
We study the Friedmann-Robertson-Walker model with dynamical dark energy modelled in terms of the equation of state $p_{x}=w_{x}(a(z)) \rho_{x}$ in which the coefficient $w_{x}$ is parameterized by the scale factor $a$ or redshift $z$. We…
Given that the dark matter and dark energy in the universe affect cosmological observables only gravitationally, their phenomenology may be described by a single stress energy tensor. True unification however requires a theory that…
In this paper, we investigate the cosmological viability of a double scalar field model motivated by warm inflation. To this end, we first set up the theoretical framework in which dark energy, dark matter and inflation are accounted for in…
Parametrizations of Equation of state parameter as a function of the scale factor or redshift are frequently used in dark energy modeling. The question investigated in this paper is if parametrizations proposed in the literature are…
In this paper, we study the possibility of building two-field models of dark energy with equation of state across -1. Specifically we will consider two classes of models: one consists of two scalar fields (Quintessence+Phantom) and another…
In this paper, we have explored the field equations of f(T, B) gravity as an extension of teleparallel gravity in an isotropic and homogeneous space time. In the basic formalism developed, the dynamical parameters are derived by…
We model a compact relativistic body with anisotropic pressures in the presence of an electric field. The equation of state is barotropic with a linear relationship between the radial pressure and the energy density. Simple exact models of…
If the generalized dynamics of K field theories (i.e., field theories with a non-standard kinetic term) is taken into account, then the possibility of so-called twin-like models opens up, that is, of different field theories which share the…
We analyse dark energy models where self-interacting three-forms or phantom fields drive the accelerated expansion of the Universe. The dynamics of such models is often studied by rewriting the cosmological field equations in the form of a…