Related papers: Dark Energy Problem in a Four-Fermion Interaction …
Astronomical measurements of the Omegas for mass density, cosmological constant lambda and curvature k are shown to be sufficient to produce a unique and detailed cosmological model describing dark energy influences based on the Friedman…
Main aim of this work is to give a suitable explanation of present accelerating universe through an acceptable interactive dynamical cosmological model. A three-fluid cosmological model is introduced in the background of…
One of the great endeavors of the past decade has been the evaluation of different observational techniques for measuring dark energy properties and of theoretical techniques for constraining models of cosmic acceleration given cosmological…
Different models of the cosmic substratum which pretend to describe the present stage of accelerated expansion of the Universe like the $\Lambda$CDM model or a Chaplygin gas, can be seen as special realizations of a holographic dark energy…
A probable solution of the cosmological constant problem was recently found. We propose that dark energy of the Universe is vacuum energy. Our Universe during its expansion is spending its vacuum energy for creation of new quantum states,…
In this paper, we have studied an interacting dark energy model. We have assumed the gravitational interaction between the matter fields i.e. between barotropic fluid and the dark energy. The dark energy evolution within the framework of…
A simple gravitational model with torsion is studied, and it is suggested that it could explain the dark matter and dark energy in the universe. It can be reinterpreted as a model using the Einstein gravitational equations where spacetime…
We consider the cosmological application of Lee-Wick theory where a field has a higher derivative kinetic operators. The higher derivative term can be eliminated by introducing a set of auxiliary fields. We investigate the cosmological…
It is shown that the vacuum condensate induced by many phenomena behaves as a perfect fluid which, under particular conditions, has zero or negative pressure. In particular, the condensates of thermal states, of fields in curved space and…
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…
As an explanation for the acceleration of the universe, we propose dark matter with self-interactions characterized by a negative pressure; there is no vacuum energy whatsoever in this Cardassian model. These self-interactions may arise due…
In this paper we study new cosmological models involving new forms of non-gravitational interaction between cold dark matter and dark energy. The main purpose is to demonstrate the applicability of the forms of interaction to the problem in…
In this article, we investigate the mechanism of cosmological expansion and inflation by modeling dark energy as a four-dimensional continuous medium, with its elastic deformation described by a four-dimensional vector field. We demonstrate…
In a four dimensional manifold formalism we study the evolutionary behavior as well as the ultimate fate of the universe, in the course of which the contribution of dark energy in these phases are investigated. At one stage we get a…
Early dark energy has emerged as one of the more promising approaches to address the Hubble tension - the statistically significant disparity between measurements of the Hubble constant made using data from different epochs in cosmic…
The Phenomenologically Emergent Dark Energy model, a dark energy model with the same number of free parameters as the flat $\Lambda$CDM, has been proposed as a working example of a minimal model which can avoid the current cosmological…
Following the approach of the induced-matter theory, we investigate the cosmological implications of a five-dimensional Brans-Dicke theory, and propose to explain the acceleration of the universe. After inducing in a four-dimensional…
A recent observation points to an excess in the expected 21-cm brightness temperature from cosmic dawn. In this paper, we present an alternative explanation of this phenomenon, an interaction in the dark sector. Interacting dark energy…
Dark Matter (DM) models providing possible alternative solutions to the small- scale crisis of standard cosmology are nowadays of growing interest. We consider DM interacting with light hidden fermions via well motivated fundamental…
We uncover the general mechanism producing the dark energy(DE). This is only based on well known quantum physics and cosmology. We show that the observed DE originates from the cosmological quantum vacuum of light particles which provides a…