Related papers: Phantom energy mediates a long-range repulsive for…
A scalar potential coupled to other fields of large disparate masses will exhibit power suppression of the quantum loop corrections from these massive fields. Quintessence fields in the dark energy regime and inflaton fields during…
Dark Energy is some of the weirdest and most mysterious stuff in the universe that tends to increase the rate of expansion of the universe. Two commonly known forms of dark energy are the cosmological constant, a constant energy density…
Cosmology with a three-form field interacting with cold dark matter is considered. In particular, the mass of the dark matter particles is assumed to depend upon the amplitude of the three-form field invariant. In comparison to coupled…
Recent many physicists suggest that the dark energy in the universe might result from the Born-Infeld(B-I) type scalar field of string theory. The universe of B-I type scalar field with potential can undergo a phase of accelerating…
The presence of phantom dark energy in brane world cosmology generates important new effects, causing a premature Big Rip singularity when we increase the presence of extra dimension and considerably competing with the other components of…
Energy transfer in the dark sector of the universe gives rise to new phenomena of special interest in modern cosmology. When dark energy is modeled as a phantom scalar field, interactions become crucial to avoid Big Rip singularities. In…
We study three different extended scalar-tensor theories of gravity by also allowing a negative sign for the kinetic term for the scalar field in the Jordan frame. Our scope is to understand how the observational constraints for these…
Scalar fields with inverse power-law effective potentials may provide a negative pressure component to the energy density of the universe today, as required by cosmological observations. In order to be cosmologically relevant today, the…
Three-forms can give rise to viable cosmological scenarios of inflation and dark energy with potentially observable signatures distinct from standard single scalar field models. In this study, the background dynamics and linear…
Important observables to reveal the nature of dark energy are the equation of state $w$ and its time derivative in units of the Hubble time $w'$. Recently, it is shown that the simplest scalar field models of dark energy (quintessence)…
We investigate non phantom tracker scalar field models as dynamical dark energy scenario. These models can alleviate the cosmic coincidence problem and transition to a cosmological constant-like behaviour at late times. Focusing on the…
The dynamical properties of a model of dark energy in which two scalar fields are coupled by a non-canonical kinetic term are studied. We show that overall the addition of the coupling has only minor effects on the dynamics of the two-field…
In light of the cosmological observations, we investigate dark energy models from the Horndeski theory of gravity. In particular, we consider cosmological models with the derivative self-interaction of the scalar field and the derivative…
When recent observational evidence and the GR+FRW+CDM model are combined we obtain the result that the Universe is accelerating, where the acceleration is due to some not-yet-understood "dark sector". There has been a considerable number of…
In present paper, we search the existence of dark energy scalar field models within in $f(R, T)$ gravity theory established by Harko et al. (Phys. Rev. D 84, 024020, 2011) in a flat FRW universe. The correspondence between scalar field…
Within the extension of the $\Lambda$CDM model, allowing for the presence of neutrinos or warm dark matter, we develop the analytical cosmological perturbation theory. It covers all spatial scales where the weak gravitational field regime…
We study the cosmological evolution of an induced gravity model with a scale symmetry breaking potential for the scalar field. The radiation to matter transition, following inflation and reheating, influences the dynamics of such a field…
We investigate the cosmological evolution of an interacting phantom energy model in which the phantom field has interaction with the dark matter. We discuss the existence and stability of scaling solutions for two types of specific…
We present a systematic exploration of dark energy and modified gravity models containing a single scalar field non-minimally coupled to the metric. Even though the parameter space is large, by exploiting an effective field theory (EFT)…
We argue that dark energy with multiple fields is theoretically well-motivated and predicts distinct observational signatures, in particular when cosmic acceleration takes place along a trajectory that is highly non-geodesic in field space.…