Related papers: Observational Constraints on Silent Quartessence
We study cosmological models with modified Chaplygin gas (in short, MCG) to determine observational constraints on its EoS parameters. The observational data of the background and the growth tests are employed. The background test data…
We investigate observational constraints on the generalized Chaplygin gas (GCG) model as the unification of dark matter and dark energy from the latest observational data: the Union SNe Ia data, the observational Hubble data, the SDSS…
In this paper we study a quintessence cosmological model in which the dark energy component is considered to be the Generalized Chaplygin Gas and the curvature of the three-geometry is taken into account. Two parameters characterize this…
In the framework of $f(Q)$ gravity, where gravity emerges from non-metricity $Q$, we explore the cosmological implications of its non-minimal coupling to matter. Inspired by the recent success of Chaplygin gas models in explaining dark…
New observational constraints on the cosmic matter density $\Omega_m$ and an effectively redshift-independent equation of state parameter $w_x$ of the dark energy are obtained while simultaneously testing the strong and null energy…
We constrain two non-flat time-evolving dark energy cosmological models by using Hubble parameter data, Type Ia supernova apparent magnitude measurements, and baryonic acoustic oscillation peak length scale observations. The inclusion of…
We investigate the limits of applicability of the quasi-static approximation in cosmologies featuring general models of dark energy or modified gravity. We show that, at best, the quasi-static approximation breaks down outside of the sound…
We investigate the cosmological constraints on the Variable Chaplygin gas model from the latest observational data: SCP Union 2.1 compilation dataset of Type Ia supernovae (SNe Ia), Pantheon sample of SNe Ia, Platinum Sample of Gamma Ray…
Quartessence is one of the alternatives to Lambda-CDM that has lately attracted considerable interest. According to this unifying dark matter/energy scenario, the Universe evolved from an early non-relativistic matter-dominated phase to a…
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…
Recently we proposed a new approach to the testing of dark energy models based on the observational data. In that work we focused particularly on quintessence models for demonstration and invoked a widely used parametrization of the dark…
Fermi energies in fullerene compounds and cuprates are extremely small as consequence of the small number of charge carriers and are comparable to the phonon frequency scale. In this situation the conventional Migdal-Eliashberg theory does…
We study the dependence of the location of the Cosmic Microwave Background Radiation (CMBR) peaks on the parameters of the generalized Chaplygin gas model, whose equation of state is given by $p = - A/\rho^{\alpha}$, where $A$ is a positive…
Unified Dark Matter models describe Dark Matter and Dark Energy as a single entity which is, in the simplest case, embodied in a perfect barotropic fluid. It is a well-established fact that small adiabatic perturbations of Unified Dark…
The equation of state of the hypothetical dark energy component, which constitutes about two thirds of the critical density of the universe, may be very different from that of a cosmological constant. Employing a phenomenological model, we…
We study the constraints on dark energy equation of state $\omega^{X}$ and the deceleration parameter $q$ from the recent observational data including Hubble data and the cosmic microwave background (CMB) radiation by using a…
We use the Type Ia Supernova gold sample data of Riess {\it et al} in order to constrain three models of dark energy. We study the Cardassian model, the Dvali-Turner gravity modified model and the generalized Chaplygin gas model of dark…
$\phi$CDM models provide an alternative to the standard $\Lambda$CDM paradigm, while being physically better motivated. These models lead to a time-dependent speed of sound for dark energy that is difficult to replicate by $w$CDM…
We present constraints on the values of $\Omega_m$, $n$, $\sigma_8$, obtained from measurements of the X-ray luminosity function of galaxy clusters as compiled in EMSS, RDCS and BCS galaxy cluster samples. The values obtained…
In this paper, we use quasars calibrated from type Ia supernova (SN Ia) to constrain cosmological models. We consider three different X-ray luminosity ($L_{X}$) - ultraviolet luminosity ($L_{UV}$) relations of quasars, i.e., the standard…