Related papers: Constraining Thawing Dark Energy using Galaxy Clus…
K-essence is a minimally-coupled scalar field whose Lagrangian density $\mathcal{L}$ is a function of the field value $\phi$ and the kinetic energy $X=\frac{1}{2}\partial_\mu\phi\partial^\mu\phi$. In the thawing scenario, the scalar field…
We present XMM-Newton studies of the total mass, gas density, temperature and entropy profiles in nearby hot and cool clusters, together with follow-up observations of distant clusters from the SHARC Survey. The observed structural and…
Cluster strong lensing cosmography is a promising probe of the background geometry of the Universe and several studies have emerged, thanks to the increased quality of observations using space and ground-based telescopes. For the first…
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…
This paper deals with a cosmological model in which the universe is filled with tachyon dark energy in order to describe current and future accelerating expansion. We obtain that the simplest condition for the regime of phantom energy to…
We consider cosmological tests of a scalar-vector-tensor gravitational model, in which the dark energy is included in the total action through a gauge invariant, electromagnetic type contribution. The ground state of dark energy,…
Models for structure formation attempt to predict the power spectrum of density perturbations in the present universe from the initial power spectrum and the nature of dark matter. Observational constraints on the power spectrum at…
We present three distinct types of models of dark energy in the form of a scalar field which is explicitly coupled to dark matter. Our construction draws from the pull-back formalism for fluids and generalises the fluid action to involve…
We compare perturbations in a fluid model of dark energy with those in a scalar field. As compared to the $\Lambda$CDM model, large scale matter power spectrum is suppressed in fluid model as well as in a generic quintessence dark energy…
We study the cluster mass function and its evolution in different models with Dark Energy arising from a self--interacting scalar field, with Ratra-Peebles and SUGRA potentials. Computations are based on a Press & Schechter approximation.…
New Cosmic Microwave Background, Galaxy Clustering and Supernovae type Ia data are increasingly constraining the dark energy component of our Universe. While the cosmological constant scenario remains consistent with these new tight…
We study the strong gravitational lensing properties of galaxy clusters obtained from N-body simulations with different kind of Dark Energy (DE). We consider both dynamical DE, due to a scalar field self--interacting through Ratra-Peebles…
The motivation of the present work is to reconstruct a dark energy model through the {\it dimensionless dark energy function} $X(z)$, which is the dark energy density in units of its present value. In this paper, we have shown that a scalar…
The nature of dark matter is increasingly constrained by cosmological data. In this paper, we examine the implications of the Cosmic Microwave Background anisotropy limits on the density of cold dark matter under different theoretical…
We investigate the prospect of constraining scalar field dark energy models using HI 21-cm intensity mapping surveys. We consider a wide class of coupled scalar field dark energy models whose predictions about the background cosmological…
We use scalar-field Lagrangians with a non-canonical kinetic term to obtain unified dark matter models where both the dark matter and the dark energy, the latter mimicking a cosmological constant, are described by the scalar field itself.…
We show that using the redshift dependence of the deep cluster abundance to detect the nature of Dark Energy is a serious challenge. We compare the expected differences between flat LCDM models, with different Omega_mo, with the difference…
Early dark energy models, for which the contribution to the dark energy density at high redshifts is not negligible, influence the growth of cosmic structures and could leave observable signatures that are different from the standard…
We present updated observational constraints on the spatially flat $\phi$CDM model, where dark energy is described by a minimally coupled scalar field $\phi$ with an inverse power-law potential $V=V_0 \phi^{-\alpha}$. Using Planck 2018 CMB…
The integrated Sachs-Wolfe (ISW) effect in the cosmic microwave background (CMB) as measured through its correlation with galaxies provides a unique opportunity to study the dynamics of the dark energy through its large scale clustering…