We derive a new interior solution for stellar compact objects in\(f\mathcal {(R)}\) gravity
assuming a differential relation to constrain the Ricci curvature scalar. To this aim, we …

We consider late-time cosmology in a (phantom) scalar-tensor theory with an exponential
potential, as a dark-energy model with equation of state parameter close to− 1 (a bit above …

It has been suggested that a possible candidate for the present accelerated expansion of the
Universe is “phantom energy”. The latter possesses an equation of state of the form ω≡ p/ρ< …

We extend the notion of phantom energy, which is generally accepted for homogeneously
distributed matter with w<-1 in the universe, on inhomogeneous spherically symmetric …

We investigate a flat Friedmann-Robertson-Walker spacetime filled with k essence and find
the set of functions F that generate three different families of extended tachyon fields and …

The high-quality cosmological data, which became available in the last decade, have
thrusted upon us a rather preposterous composition for the universe which poses one of the …

Determining the mechanism behind the current cosmic acceleration constitutes a major
question nowadays in theoretical physics. If the dark energy route is taken, this problem may …

We study the entropy of a FRW universe filled with dark energy (cosmological constant,
quintessence, or phantom). For the general or time-dependent equation of state p= w ρ the …

We extend our previous analysis of cosmological supernova type Ia data [CITE] to include
three recent compilation of data sets. Our analysis ignores the possible correlations and …

Using mock data for the Hubble diagrams of type Ia supernovae (SNIa) and quasars (QSOs)
generated based on the standard model of cosmology, and using the least-squares method …