Related papers: Models for Little Rip Dark Energy
We argue that, for generic string compactifications, dark energy is likely to signal the beginning of the end of our universe, perhaps even through decompactification, with possible implications for the cosmological coincidence problem.…
We revise the cosmological interaction between dark energy and dark matter. More precisely, we focus on models that support compartmentalization or co-existence in the dark sector of the universe. Within the framework of a homogeneous and…
We investigate the implications of energy conditions on cosmological compactification solutions of the higher-dimensional Einstein field equations. It is known that the Strong Energy Condition forbids time-independent compactifications to…
To explain the acceleration of the cosmological expansion researchers have considered an unusual form of mass-energy generically called dark energy. Dark energy has a ratio of pressure over mass density which obeys $w=p/\rho <-1/3$. This…
Theories with several hundred axion fields have enormous numbers of distinct meta-stable minima. A small fraction of these local minima have vacuum energy compatible with current measurements of dark energy. The potential also contains…
In this paper we perform a thorough dynamical systems analysis of the cubic galileon model non-minimally coupled to the dark matter. Three well-known classes of interacting models are considered where the energy exchange between the dark…
We investigate a class of models for dark matter and/or negative-pressure, dynamical dark energy consisting of ``spintessence,'' a complex scalar field $\phi$ spinning in a U(1)-symmetric potential $V(\phi)=V(|\phi|)$. As the Universe…
We consider cosmological dynamics in the theory of gravity with the scalar field possessing the nonminimal kinetic coupling to curvature given as $\kappa G^{\mu\nu}\phi_{,\mu}\phi_{,\nu}$, and the Higgs-like potential…
We discuss a cosmological model where the universe shrinks rather than expands during the radiation and matter dominated periods. Instead, the Planck mass and all particle masses grow exponentially, with the size of atoms shrinking…
Dark energy models due to a slowly evolving scalar (quintessence) field $\phi$ are studied for various potentials $V(\phi)$ in a universe with negative curvature. The potentials differ in whether they possess a minimum at $\phi=0$ or are…
We study the phantom inflation in little rip cosmology, in which the current acceleration is driven by the field with the parameter of state w < -1, but since w tends to -1 asymptotically, the rip singularity occurs only at infinite time.…
We investigate the evolution of a universe with a decaying cosmological term (vacuum energy) that is assumed to be a function of the scale factor. In this model, while the cosmological term increases to the early universe, the radiation…
Spatially homogeneous models with a scalar field non-minimally coupled to the space-time curvature or to the ordinary matter content are analysed with respect to late-time asymptotic behaviour, in particular to accelerated expansion and…
In this work, we investigate the cosmological dynamics of an anisotropic Universe within the framework of $f(R,T)$ gravity by incorporating pressureless dark matter and the dark energy models. The analysis is carried out in a Bianchi type-I…
We propose the simplest model of teleparallel dark energy with purely a non-minimal coupling to gravity but no self-potential, a single model possessing various interesting features: simplicity, self-potential-free, the guaranteed late-time…
In order to understand the nature of the accelerating expansion of the late-time universe, it is important to experimentally determine whether dark energy is a cosmological constant or dynamical in nature. If dark energy already exists…
We present a prototype model that resolves the cosmological constant problem using matter alone, i.e., without modifying gravity. Its generic cosmological solutions adjust an arbitrarily large, negative dark energy to a positive value…
The discovery of accelerated expansion of the universe opened the possibility of new scenarios for the doom of our spacetime, besides aeternal expansion and a final contraction. In this paper we review the chances which may await our…
Taking up four model universes we study the behaviour and contribution of dark energy to the accelerated expansion of the universe, in the modified scale covariant theory of gravitation. Here, it is seen that though this modified theory may…
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…