Related papers: Observational Constraints on Chaplygin Quartessenc…
The search for the physical mechanism underlying the observational evidence for the acceleration of the recent universe is a compelling goal of modern fundamental cosmology. Here we quantitatively study a class of homogeneous and isotropic…
The standard model of cosmology, {\Lambda}CDM, is the simplest model that matches the current observations, but it relies on two hypothetical components, to wit, dark matter and dark energy. Future galaxy surveys and cosmic microwave…
We use all available baryon acoustic oscillation distance measurements and Hubble parameter data to constrain the cosmological constant $\Lambda$, dynamical dark energy, and spatial curvature in simple cosmological models. We find that the…
Observations conducted over the last few decades show that the expansion of the Universe is accelerating. In the standard model of cosmology, this accelerated expansion is attributed to a dark energy in the form of a cosmological constant.…
If the dark energy is modelled as a relativistic elastic solid then the standard CDM and $\Lambda$CDM models, as well as lattice configurations of cosmic strings or domain walls, are points in the two-dimensional parameter space $(w,c_{\rm…
We present constraints on extensions to the flat $\Lambda$CDM cosmological model by varying the spatial curvature $\Omega_K$, the sum of the neutrino masses $\sum m_\nu$, the dark energy equation of state parameter $w$, and the Hu-Sawicki…
We present cosmological parameter constraints on flat cosmologies dominated by dark energy using various cosmological data including the recent Archeops angular power spectrum measurements. A likelihood analysis of the existing Cosmic…
We study Quintessence cosmologies in the context of scalar-tensor theories of gravity, where a scalar field $\phi$, assumed to provide most of the cosmic energy density today, is non-minimally coupled to the Ricci curvature scalar $R$. Such…
Any theory invoked to explain cosmic acceleration predicts consistency relations between the expansion history, structure growth, and all related observables. Currently there exist high-quality measurements of the expansion history from…
We study observational signatures of non-gravitational interactions between the dark components of the cosmic fluid, which can be either due to creation of dark particles from the expanding vacuum or an effect of the clustering of a…
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…
In this paper, after reconstructing the redshift evolution of the Hubble function by adopting Gaussian process techniques, we estimate the best-fit parameters for some flat Friedmann cosmological models based on a Modified Chaplygin Gas…
A new class of braneworld models displaying late-time phantom acceleration without resorting to a phantom fluid is presented. In this scenario expansion is fuelled by dark matter together with some effective dark energy capable of crossing…
Recent measurements of the parameters of the Concordance Cosmology Model ($\Lambda$CDM) done in the low-redshift Universe with Supernovae Ia/Cepheids, and in the distant Universe done with Cosmic Microwave Background (CMB) imply different…
We perform a detailed analysis of a theoretically motivated dark energy quintessence model which interacts with the dark matter sector of the universe. Utilising the current observational datasets from the Cosmic Microwave Background,…
In this paper the accelerating expansion of our universe at the late cosmic evolution time in a generally modified (extended) \emph{Chaplygin gas} (Dark Fluid) model is detailed, which is characterized by two parameters ($m$, $\alpha$).…
Recent measurements of type Ia supernovae as well as other concordant observations suggest that the expansion of our universe is accelerating. A dark energy component has usually been invoked as the most feasible mechanism for the…
We investigate the observational viability of a quadratic dark energy expansion (QDEE) model as a phenomenological extension of the standard $\Lambda\mathrm{CDM}$ cosmological framework. This approach introduces the additional degrees of…
Thawing quintessence scalar field models with the various potential forms to explain the late-time cosmic acceleration are compared to the {\Lambda}CDM model in detail by analyzing cosmological parameters with a set of observational data…
We investigate cosmological constraints on K-mouflage models of modified gravity. We consider two scenarios: one where the background evolution is free to deviate from $\Lambda$CDM (K-mouflage) and another one which reproduces a…