Configurational entropy in Chaplygin gas models

Entropy perturbations in quartessence Chaplygin models

We show that entropy perturbations can eliminate instabilities and oscillations, in the mass power spectrum of the quartessence Chaplygin models. Our results enlarge the current parameter space of models compatible with large scale structure and cosmic microwave background (CMB) observations.

Generalized Chaplygin Gas Models tested with SNIa

The Generalized Chaplygin Gas (GCG) with the equation of state p = − A ρ was recently proposed as a candidate for dark energy in the Universe. In this paper we confront the GCG with SNIa data using avaliable samples. Specifically we have tested the GCG cosmology in three different classes of models with (1) Ωm = 0.3, ΩCh = 0.7; (2) Ωm = 0.05, ΩCh = 0.95 and (3) Ωm = 0, ΩCh = 1, as well as a mod...

Viscous Generalized Chaplygin Gas

Viscous GCG(generalized Chaplygin gas) cosmology is discussed, assuming that there is bulk viscosity in the linear barotropic fluid and GCG. The dynamical analysis indicates that the phase wg = −1 + √ 3γκτg/(γ − √ 3κτγ) is a dynamical attractor and the equation of state of GCG approaches it from either wg > −1 or wg < −1 depending on the choice of its initial cosmic density parameter and the ra...

Detectability of Cosmic Topology in Generalized Chaplygin Gas Models

If the spatial section of the universe is multiply connected, repeated images or patterns are expected to be detected observationally. However, due to the finite distance to the last scattering surface, such pattern repetitions could be unobservable. This raises the question of whether a given cosmic topology is detectable, depending on the values of the parameters of the cosmological model. We...

Chaplygin gas dominated anisotropic brane world cosmological models