Related papers: Cosmological Evolution of Pilgrim Dark Energy
We demonstrate two periodic or quasi-periodic generalizations of the Chaplygin gas (CG) type models to explain the origins of dark energy as well as dark matter by using the Weierstrass $\wp(t)$, $\sigma(t)$ and $\zeta(t)$ functions with…
In this paper, we investigate the behavior of equation of state parameter and energy density for dark energy in the framework of f(T) gravity. For this purpose, we use anisotropic LRS Bianchi type I universe model. The behavior of…
The consideration of dark energy's quanta, required also by thermodynamics, introduces its chemical potential into the cosmological equations. Isolating its main contribution, we obtain solutions with dark energy decaying to matter or…
We review a dynamical dark energy model scarcely studied in the literature and we introduce two possible generalizations. We discuss separately the behavior of the original model and a minimal extension of it by exploring some early and…
We considered the phantom cosmology with a lagrangian $\displaystyle L=\frac{1}{\eta}[1-\sqrt{1+\eta g^{\mu\nu}\phi_{, \mu}\phi_{, \nu}}]-u(\phi)$, which is original from the nonlinear Born-Infeld type scalar field with the lagrangian…
We develop here a relatively simple description of dark energy based on the dynamics of non-minimally coupled to gravity phantom scalar field which, in limit, corresponds to cosmological constant. The dark energy equation of state, obtained…
In this study, we will look at an interacting dark energy model. In the framework of Friedmann-Robertson-Walker (FRW) space-time, we have made the hypothesis of an interacting scheme between two fields (dark matter (DM) and dark energy…
We consider the interacting holographic dark energy with new infrared cutoff (involving Hubble parameter and its derivative) in non-flat universe. In this context, we obtain the equation of state parameter which evolutes the universe from…
In this talk we present a model of the universe in which dark energy is modelled explicitely with both a dynamical quintessence field and a cosmological constant. Our results confirm the possibility of a collapsing universe (for a given…
We study the dynamical properties of dark energy based on a large family of PADE parameterizations for which the dark energy density evolves as a ratio between two polynomials in the scale factor of the universe. Using the latest…
We investigate various dark energy models by taking into account the thermal effects induced from Hawking radiation on the apparent horizon of the Universe, for example near a finite-time future singularity. If the dark energy density…
We consider late-time cosmology in a (phantom) scalar-tensor theory with an exponential potential, as a dark energy model with equation of state parameter close to -1 (a bit above or below this value). Scalar (and also other kinds of)…
In standard cosmology, with the evolution of the universe, the matter density and thermodynamic pressure gradually decreases. Also in course of evolution, the matter in the universe obeys (or violates) some restrictions or energy…
A huge amount of good quality astrophysical data converges towards the picture of a spatially flat universe undergoing the today observed phase of accelerated expansion. This new observational trend is commonly addressed as Precision…
We use the phase plane analysis technique of Madsen and Ellis to consider a universe with a true cosmological constant as well as a cosmological "constant" that is decaying. Time symmetric dynamics for the inflationary era allows eternally…
We investigate observational consequences of the early episodically dominating dark energy on the evolution of cosmological structures. For this aim, we introduce the minimally coupled scalar field dark energy model with the…
We consider scalar field models of dark energy interacting with dark matter through a coupling proportional to the contraction of the four-derivative of the scalar field with the four-velocity of the dark matter fluid. The coupling is…
In this work we use cosmography to alleviate the degeneracy among cosmological models, proposing a way to parameterize matter and dark energy in terms of cosmokinematics quantities. The recipe of using cosmography allows to expand…
We perform an empirical consistency test of General Relativity/dark energy by disentangling expansion history and growth of structure constraints. We replace each late-universe parameter that describes the behavior of dark energy with two…
We propose a Friedmann-Lemaitre-Robertson-Walker cosmological model with a scalar field that represents dark energy. A new parametrization of the deceleration parameter is introduced of the form $q = 1 + \eta (1 + \mu a^{\eta})$ where…