Related papers: Step potentials for Dark Energy
We do a detailed analysis of a well-theoretically motivated interacting dark energy scalar field model with a time-varying interaction term. Using current cosmological datasets from CMB, BAO, Type Ia Supernova, $H(z)$ measurements from…
We propose a dynamical (quintessence) model of dark energy in the current universe with a renormalizable (Higgs-like) scalar potential. We prove the viability of our model (after fine tuning) for the certain range of the average scalar…
We employ the superpotential technique for the reconstruction of cosmological models with a non-minimally coupled scalar field evolving on a spatially flat Friedmann-Robertson-Walker background. The key point in this method is that the…
We study the interaction between dark matter and dark energy, with dark energy described by a scalar field having a double exponential effective potential. We discover conditions under which such a scalar field driven solution is a late…
We generalize quintom to include the tachyonic kinetic term along with the classical one. For such a model we obtain the expressions for energy density and pressure. For the spatially flat, homogeneous and isotropic Universe with…
We explore the properties of dark energy from recent observational data, including the Gold Sne Ia, the baryonic acoustic oscillation peak from SDSS, the CMB shift parameter from WMAP3, the X-ray gas mass fraction in cluster and the Hubble…
The background evolution of an accelerated, dark energy dominated universe is aptly described by non-canonical tachyon scalar field models. The accelerated expansion of the universe is determined by the choice of a suitable scalar field…
Cosmological parameters and dark energy (DE) behavior are generally constrained assuming \textit{a priori} models. We work out a model-independent reconstruction to bound the key cosmological quantities and the DE evolution. Through the…
The reconstruction of scalar-field dark energy models is studied for a general Lagrangian density $p(\phi, X)$, where $X$ is a kinematic term of a scalar field $\phi$. We implement the coupling $Q$ between dark energy and dark matter and…
Observing dark energy dynamics is the most important aspect of the dark energy research. In this paper we perform an analysis of the constraints on the property of dark energy from the current astronomical observations. We pay particular…
We assess the viability of successful reconstruction of the evolution of the dark energy equation of state using varying fundamental couplings, such as the fine structure constant or the proton-to-electron mass ratio. We show that the same…
Hints of a dynamical dark-energy equation of state have appeared in several combined cosmological probes. However, such indications may instead arise from the intrinsic likelihood geometry of individual datasets, residual inter-probe…
The coupling between the dark components provides a new approach to mitigate the coincidence problem of cosmological standard model. In this paper, dark energy is treated as a fluid with a constant equation of state, whose coupling with…
We consider Brans-Dicke type nonminimally coupled scalar field as a candidate for dark energy. In the conformally transformed Einstein's frame, our model is similar to {\it coupled quintessence} model. In such models, we consider potentials…
Models where the dark energy is a scalar field with a non-standard Dirac-Born-Infeld (DBI) kinetic term are investigated. Scaling solutions are studied and proven to be attractors. The corresponding shape of the brane tension and of the…
We propose a Friedmann-Lemaitre-Robertson-Walker cosmological model with a scalar field that represents dark energy. A new parametrization of the deceleration parameter is introduced of the form $q = 1 + \eta (1 + \mu a^{\eta})$ where…
We present a new mechanism for cosmic acceleration consisting of a scalar field coupled to a triplet of classical U(1) gauge fields. The gauge fields are arranged in a homogeneous, isotropic configuration, with both electric- and…
We develop a formalism to characterize the redshift evolution of the dark energy potential. Our formalism makes use of quantities similar to the Horizon-flow parameters in inflation and is general enough that can deal with multiscalar…
The possibility of a non-gravitational interaction between the dark matter and the dark energy has been reconstructed using some recent datasets. The crucial aspect is that the interaction is not parametrized at the outset, but rather…
The recent data release DR2 from the Dark Energy Spectroscopic Instrument (DESI) has reinforced compelling evidence supporting the dynamical nature of dark energy. In this respect, we here explore a two-scalar field cosmological model,…