Related papers: Constraining Evolution of Quintessence with CMB an…
Recently H(z) data obtained from differential ages of galaxies have been proposed as a new geometrical probe of dark energy. In this paper we use those data, combined with other background tests (CMB shift and SNIa data), to constrain a set…
We propose a new non-minimally coupled quintessence model to account for the late-time dark energy dynamics indicated by recent DESI measurements. Within this framework, the quintessence density begins to decrease only when it starts to…
We study the evolution of galaxy clustering in various cosmological models with quintessence. We investigate how the analytical predictions vary with change of dark energy equation of state $w_X$. Comparing these predictions against…
Quintessence, a scalar field model, has been proposed to account for the acceleration of the Universe at present. We discuss how accurately quintessence models are discriminated by future cosmological surveys, which include experiments of…
We examine the status of various dark energy-models in light of the recently observed SN 1997ff at z \approx 1.7. The modified data still fit a pure cosmological constant \Lambda or a quintessence with an equation of state similar to that…
As an alternative to the popular parametrisations of the dark energy equation of state, we construct a quintessence model where the scalar field has a linear dependence on the number of e-folds. Constraints on more complex models are…
We examine the constraints that can be obtained on standard cold dark matter models from the most currently used data set: CMB anisotropies, type Ia supernovae and the SDSS luminous red galaxies. We also examine how these constraints are…
In this work, we have proposed a general dark energy density parametrization to study the evolution of the universe. We have also constrained the model parameters using the combination of Type Ia supernova (SNIa), baryonic acoustic…
Dark energy can be investigated in two complementary ways, by considering either general parameterizations or physically well-defined models. Following the second route, we explore the constraints on quintessence models where the…
A new component of the cosmic medium, a light scalar field or ''quintessence '', has been proposed recently to explain cosmic acceleration with a dynamical cosmological constant. Such a field is expected to be coupled explicitely to…
The framework for considering the astronomical and cosmological observations in the context of scalar-tensor quintessence in which the quintessence field also accounts for a time dependence of the gravitational constant is developed. The…
Recent cosmological observations strongly suggest that the universe is dominated by an unknown form of energy with negative pressure. Why is this dark energy density of order the critical density today? We propose that the dark energy has…
Recent measurements suggest our universe has a substantial dark energy component, which is usually interpreted in terms of a cosmological constant. Here we examine how much the form of this dark energy can be modified while still retaining…
Observations of high redshift supernovae imply an accelerating Universe which can only be explained by an unusual energy component such as vacuum energy or quintessence. To assess the ability of current and future supernova data to…
Recent astronomical observations of SNIa, CMB, as well as BAO in the Sloan Digital Sky Survey, suggest that the current Universe has entered a stage of an accelerated expansion with the transition redshift at $z \simeq 0.5$. While the…
Prompted by the recent MAXIMA-1 and BOOMERANG-98 measurements of the cosmic microwave background (CMB) anisotropy power spectrum, and motivated by the results from the observation of high-redshift Type Ia supernovae, we investigate CMB…
We present constraints on the dark energy equation-of-state parameter, w=P/(rho c^2), using 60 Type Ia supernovae (SNe Ia) from the ESSENCE supernova survey. We derive a set of constraints on the nature of the dark energy assuming a flat…
The consensus of opinion in cosmology is that the Universe is currently undergoing a period of accelerated expansion. With current and proposed high precision experiments it offers the hope of being able to discriminate between the two…
The accelerating expansion of the universe is the most surprising cosmological discovery in many decades. In this short review, we briefly summarize theories for the origin of cosmic acceleration and the observational methods being used to…
We investigate the possibility of using cosmological observations to probe and constrain an imperfect dark energy fluid. We consider a general parameterization of the dark energy component accounting for an equation of state, speed of sound…