相关论文: Classifying the Future of Universes with Dark Ener…

In this work we review some of the theoretical efforts and experimental evidences related to Dark matter and Dark energy problems in the universe. These dilemmas show us how incomplete our knowledge of gravity is, and how our concepts about…

While modelling our late time cosmically accelerated universe, it is popular to involve different dark energy models, the equation of state of which can be taken as a function of the redshift and some unknown parameters. Barboza and Alcaniz…

The Standard Model of cosmology of the 1980's was based on a remarkable interplay of ideas from particle theory, experiment and astrophysical observations. That model is now dead, and has been replaced by something far more bizarre.…

Entangled states in the universe may change interpretation of observations and even revise the concept of dark energy.

Last year observations had a profound impact on our views on the amount and nature of dark matter in the universe. We give a brief review of the recent history of dark matter models beyond the pure cold dark matter universe. In view of the…

The concept of oscillatory Universe appears to be realistic and buried in the dynamic dark energy equation of state. We explore its evolutionary history under the frame work of general relativity. We observe that oscillations do not go…

As we follow our Universe to early times, we find that matter was crushed to high densities, somewhat similar to the behavior at a black hole singularity. String theory has made progress in explaining the internal structure of black holes,…

Using a specific model for the expansion rate of the Universe as a function of scale factor, it is demonstrated that the equation of state of the dark energy cannot be determined uniquely from observations at redshifts $z\lesssim{\rm a…

Astrophysical observations provide a picture of the universe as a 4-dim homogeneous and isotropic flat space-time dominated by an unknown form of dark energy. To achieve such a cosmology one has to consider in the early universe an…

One of the key issues in cosmology is to establish the nature of dark energy, and to determine whether the equation of state evolves with time. When estimating this from distance measurements there is a degeneracy with the matter density.…

The evolution of dark energy density is a crucial quantity in understanding the nature of dark energy. Often, the quantity is described by the so-called equation of state, that is the ratio of dark energy pressure to its density. In this…

Discoveries in the last few years have revolutionized our knowledge of the universe and our ideas of its ultimate fate. Measurements of the expansion of the universe show that it is not slowing down under normal gravity but accelerating due…

I review the observational prospects to constrain the equation of state parameter of dark energy and I discuss the potential of future imaging and redshift surveys. Bayesian model selection is used to address the question of the level of…

Here, creation of the universe is obtained only from gravity sector. The dynamical universe begins with two basic ingredients (i) vacuum energy, also called dark energy (as vacuum energy is not observed) and (ii) background radiation. These…

Dark energy is an elusive concept, which has been introduced two decades ago in order to make the acceleration of the universe a comprehensible phenomenon. However, the nature of this energy is far from being understood, both from a…

Measurements suggest that our universe has a substantial dark energy component. The most recent data on type Ia supernovae give a dark energy density which is in good agreement with other measurements if the dark energy is assumed to be a…

We study cosmological perturbations in a model of unified dark matter and dark energy with a sharp transition in the late-time universe. The dark sector is described by a dark fluid which evolves from an early stage at redshifts $z > z_C$…

We examine the consequences of a universe with a non-constant cosmological term in Einstein's equations and find that the Bianchi identities reduce to the first law of thermodynamics when cosmological term is identified as being…

We discuss cosmological models for an eternal universe. Physical observables show no singularity from the infinite past to the infinite future. While the universe is evolving, there is no beginning and no end - the universe exists forever.…

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…