Dark energy equation of state can be effectively described by that of a barotropic fluid. The
barotropic fluid model describes the background evolution and the functional form of the …

We solve analytically and numerically the generalized Einstein equations in scalar-tensor
cosmologies to obtain the evolution of dark energy and matter linear perturbations. We …

The accelerated expansion of the universe is a rather established fact in cosmology and
many different models have been proposed as a viable explanation. Many of these models …

Quintessence can cluster only on horizon scales. What is the effect on the observed matter
distribution? To answer this, we need a relativistic approach that goes beyond the standard …

Observations have confirmed the accelerated expansion of the universe. The accelerated
expansion can be modelled by invoking a cosmological constant or a dynamical model of …

We show that a phenomenological form of energy density for the scalar field can provide the
required transition from decelerated (q> 0) to accelerated expansion (q< 0) phase of the …

A non-canonical scalar tachyon field is a viable candidate for dark energy and has been
found to be in good agreement with observational data. Background data alone cannot …

We study the general evolution of spherical overdensities for the thawing class of dark
energy models. We model dark energy with scalar fields having canonical as well as non …

Dark energy perturbation affects the growth of matter perturbations even in scenarios with
noninteracting dark energy. We investigate the integrated Sachs-Wolfe effect in various …

In the local Universe, the masses of supermassive black holes (SMBHs) appear to correlate
with the physical properties of their hosts, including the mass of the dark matter haloes. At …