Related papers: Coincidence Problem in YM Field Dark Energy Model
The interacting and holographic dark energy models involve two important quantities. One is the characteristic size of the holographic bound and the other is the coupling term of the interaction between dark energy and dark matter. Rather…
We show that all cosmological models with an accelerated stationary global attractor reduce asymptotically to a dark energy field with an exponential potential coupled linearly to a perfect fluid dark matter. In such models the abundance of…
A coupled dark energy model is considered, in which dark energy is represented by a generalized three-form field and dark matter by dust. By assuming the functions $N$ and $I$ in the model's Lagrangian as two power-law functions of the…
We investigate several varying-mass dark-matter particle models in the framework of phantom cosmology. We examine whether there exist late-time cosmological solutions, corresponding to an accelerating universe and possessing dark energy and…
Motivated by the cosmological constant and the coincidence problems, we consider a cosmological model where the dark sectors are interacting together through a phenomenological decay law $\dot{\rho}_{\Lambda}=Q\rho_{\Lambda}^n$ in a FRW…
Models where Dark Matter and Dark Energy interact with each other have been proposed to solve the coincidence problem. We review the motivations underlying the need to introduce such interaction, its influence on the background dynamics and…
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…
We discuss cosmological models involving homogeneous and isotropic Yang-Mills (YM) fields. Such models were proposed recently as an alternative to scalar models of cosmic acceleration. There exists a unique SU(2) YM configuration…
Most of the models leading to a current state of cosmic accelerated expansion fail to address the coincidence problem, i.e., that the dark energy density and the energy density of the matter fluid are of the same order precisely today. We…
In this paper we investigate the evolution of the viscous dark energy (DE) interacting with the dark matter (DM) in the Einstein cosmology model. Using the linearizing theory of the dynamical system, we find, in our model, there exists a…
We explore the possibility of having a composite (self-conserved) dark energy (DE) whose dynamics is controlled by the quantum running of the cosmological parameters. We find that within this scenario it is feasible to find an explanation…
The early cosmic inflation, when taken along with the recent observations that the universe is currently dominated by a low density vacuum energy, leads to at least two potential problems which modern cosmology must address. First, there is…
We study a cosmological model in which phantom dark energy is coupled to dark matter by phenomenologically introducing a coupled term to the equations of motion of dark energy and dark matter. This term is parameterized by a dimensionless…
The energy densities of matter and the vacuum are currently observed to be of the same order of magnitude: $(\Omega_{m 0} \approx 0.3) \sim (\Omega_{\Lambda 0} \approx 0.7)$. The cosmological window of time during which this occurs is…
The two most popular candidates for dark energy, i.e. a cosmological constant and quintessence, are very difficult to distinguish observationally, mostly because the quintessence field does not have sizable fluctuations. We study a scalar…
We explore the fate of the universe given the possibility that the density associated with `dark energy' may decay slowly with time. Decaying dark energy is modeled by a homogeneous scalar field which couples minimally to gravity and whose…
It is a known fact that a quintessence model with $w_q < -1$ fits the publicly available Super Nova (SN) type Ia data better than a model with cosmological constant or $w_q > -1$. Two types of models have this property: Scalar fields with…
Dark energy models which alter the relative scaling behavior of dark energy and matter could provide a natural solution to the cosmic coincidence problem - why the densities of dark energy and dark matter are comparable today. A generalized…
We test the viability of a single fluid cosmological model containing a transition from a dark-matter-like regime to a dark-energy-like regime. The fluid is a k-essence scalar field with a well-defined Lagrangian. We constrain its model…
In this paper we revisit the dynamical dark energy model building based on single scalar field involving higher derivative terms. By imposing a degenerate condition on the higher derivatives in curved spacetime, one can select the models…