Related papers: Alternatives to Quintessence Model Building
The cosmological model of the modified Chaplygin gas interacting with cold dark matter is studied. Our attention is focused on the final state of universe in the model. It turns out that there exists a stable scaling solution, which…
We study the dynamics of a quintessence model based on two interacting scalar fields. The model can account for the (recent) accelerated expansion of the Universe suggested by astronomical observations. Acceleration can be permanent or…
Motivated by recent developments in particle physics and cosmology, there has been growing interest in an unified description of dark matter and dark energy scenarios. In this paper we explore observational constraints from age estimates of…
We explore quintessence models of dark energy which exhibit non-minimal coupling between the dark matter and the dark energy components of the cosmic fluid. The kind of coupling chosen is inspired in scalar-tensor theories of gravity. We…
We investigate the linear growth function for the large scale structures of the universe considering modified Chaplygin gas as dark energy. Taking into account observational growth data for a given range of redshift from the Wiggle-Z…
We argue that interactions in the dark sector may have a crucial impact on the cosmological dynamics. In particular, the future cosmic evolution may be very different from that predicted by the LCDM model. An example is a scenario in which…
We consider a model of interacting cosmological constant/quintessence, where dark matter and dark energy behave as, respectively, two coexisting phases of a fluid, a thermally excited Bose component and a condensate, respectively. In a…
Dynamical models for dark energy are an alternative to the cosmological constant. It is important to investigate properties of perturbations in these models and go beyond the smooth FRLW cosmology. This allows us to distinguish different…
We choose a modified Chaplygin Gas Dark energy model for considering some its cosmological behaviors. In this regards, we study different Rip singularity scenarios and bouncing model of the universe in context of this model. We show that by…
We discuss some cosmological consequences of a general model of coupled quintessence in which the phenomenological coupling between the cold dark matter and dark energy is a function of the cosmic scale factor $\epsilon(a)$. This class of…
Despite its dominance in the present universe's energy budget, dark energy is the least understood component in the universe. Although there is a popular model for the dynamical dark energy, the quintessence scalar, the investigation is…
Interacting quintessence models have been proposed to explain or, at least, alleviate the coincidence problem of late cosmic acceleration. In this paper we are concerned with two aspects of these kind of models: (i) the dynamical evolution…
We present a scalar-field formulation of the generalized Chaplygin gas (GCG) and modified Chaplygin gas (MCG) models, in which the cosmic fluid dynamics are reproduced by canonical Lagrangians with analytically derived energy density…
With considerations of the recently released WMAP year three and supernova legacy survey (SNLS) data set analysis that favors models similar to the $% \Lambda CDM$ model by possibly mild fluctuations around the vacuum energy or the…
Any unified dark matter cosmology can be decomposed into dark matter interacting with vacuum energy, without introducing any additional degrees of freedom. We present observational constraints on an interacting vacuum plus dark energy…
The standard model of cosmology relies on the existence of two components, "dark matter" and "dark energy", which dominate the expansion of the Universe. There is no direct proof of their existence, and their nature is still unknown. Many…
The hypothesis that dark matter and dark energy are unified through the Chaplygin gas is reexamined. Using generalizations of the spherical model which incorporate effects of the acoustic horizon we show that an initially perturbative…
Despite the interest in dark matter and dark energy, it has never been shown that they are in fact two separate substances. We provide the first strong evidence that they are separate by ruling out a broad class of so-called unified dark…
A new class of braneworld models displaying late-time phantom acceleration without resorting to a phantom fluid is presented. In this scenario expansion is fuelled by dark matter together with some effective dark energy capable of crossing…
We model the nonlinear growth of cosmic structure in different dark energy models, using large volume N-body simulations. We consider a range of quintessence models which feature both rapidly and slowly varying dark energy equations of…