Related papers: Quintom phase-space: beyond the exponential potent…
The properties of future singularities are investigated in the universe dominated by dark energy including the phantom-type fluid. We classify the finite-time singularities into four classes and explicitly present the models which give rise…
We examine the embedding of dark energy in high energy models based upon supergravity and extend the usual phenomenological setting comprising an observable sector and a hidden supersymmetry breaking sector by including a third sector…
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…
This work applies the principles of quantum cosmology to examine models incorporating a quintom field. Specifically, three distinct models are analyzed: a simplified toy model, a model featuring an exponential quintom potential, and one…
We consider the ghost-condensate model of dark energy with a generic potential term. The inclusion of the potential is shown to give greater freedom in realising the phantom regime. The self-consistency of the analysis is demonstrated using…
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…
A model of phantom scalar field dark energy under exponential potential coupling to barotropic dark matter fluid in loop quantum cosmology is addressed here. We derive a closed-autonomous system for cosmological dynamics in this scenario.…
A class of dynamical dark energy models, dubbed Spinor Quintom, can be constructed by a spinor field $\psi$ with a nontraditional potential. We find that, if choosing suitable potential, this model is able to allow the equation-of-state to…
In this paper we study in detail the phase space of a cosmological system consisting of two coupled fluids, namely a dark energy fluid coupled with a superfluid dark matter fluid. The dark matter fluid is assumed to have a superfluid…
From the analysis of Supernova Ia data alongwith Observational Hubble Data (OHD) and Baryon Acoustic Oscillation (BAO) data, we attempt to find out the nature of a scalar potential that may be responsible for the Dark Energy of the…
The dynamics of the Brans-Dicke theory with a quadratic scalar field potential function and barotropic matter is investigated. The dynamical system methods are used to reveal complexity of dynamical evolution in homogeneous and isotropic…
We study the general features of the dynamics of the phantom field in the cosmological context. In the case of inverse coshyperbolic potential, we demonstrate that the phantom field can successfully drive the observed current accelerated…
We investigate the realization of quintom scenario for dynamical dark energy within modified gravity theories that can efficiently fit the recent observational datasets. Starting from a general effective field theory formulation of dark…
Current observations seem to mildly favor an evolving dark energy with the equation of state getting across -1. This form of dark energy, dubbed Quintom, is studied phenomenologically in this paper with an oscillating equation of state. We…
The late time acceleration of the Universe can be characterized in terms of an extra, time dependent, component of the universe -- dark energy. The simplest proposal for dark energy is a scalar-tensor theory -- quintessence -- which…
Recently, attempts have been made to understand the apparent near coincidence of the present dark energy and matter energy in terms of a dynamical attractor-like solution for the evolution of a scalar field. In these models the field…
The present paper deals to the quintom model of dark energy. We introduce a first-order formalism, which shows how to relate the potential that specifies the scalar field model to Hubble parameter. Reviewing briefly the quintom scenario of…
The current accelerating phase of the evolution of the universe is considered by constructing most economical cosmic models that use just general relativity and some dominating quantum effects associated with the probabilistic description…
We obtain conditions for the existence and stability of de Sitter attractors in the phase space of spatially homogeneous and isotropic cosmology in generalized theories of gravity (including non-linear and scalar-tensor theories). These…
With a parametric form of the equation of state parameter of dark energy, a quintessence potential has been reconstructed. The potential is found to be a generalization of a double exponential potential. The constraints on the parameters…