相关论文: Classifying the Future of Universes with Dark Ener…
Our universe is observed to be accelerating due to the dominant dark energy with negative pressure. The dark energy equation of state (w) holds a key to understanding the ultimate fate of the universe. The cosmic voids behave like bubbles…
In the context of models where the dark energy density $\rD$ is a random variable, anthropic selection effects may explain both the "old" cosmological constant problem and the "time coincidence". We argue that this type of solution to both…
We present a study of cosmological implications of generic dark matter decays. We consider two-body and many-body decaying scenarios. In the two-body case the massive particle has a possibly relativistic kick velocity and thus possesses a…
The consideration of dark energy's quanta, required also by thermodynamics, introduces its chemical potential into the cosmological equations. Isolating its main contribution, we obtain solutions with dark energy decaying to matter or…
A general equation of state is considered for analysing the possible behaviors for (Early) dark energy that alleviates the Hubble parameter tension problem. By departing from the possible evolution for the (Early) dark energy density and…
Considering that the universe is filled with the nonrelativistic matter and dark energy and each component is respectively satisfied with its conservation condition in the absence of their interaction, we give the change rate of the…
The age of the universe in the Big Bang model can be calculated from three parameters: Hubble's constant, h; the mass density of the universe, Omega_m; and the cosmological constant, Omega_lambda. Recent observations of the cosmic microwave…
A huge amount of good quality astrophysical data converges towards the picture of a spatially flat universe undergoing the today observed phase of accelerated expansion. This new observational trend is commonly addressed as Precision…
We study the structure formation by investigating the spherical collapse model in the context of new agegraphic dark energy model in flat FRW cosmology. We compute the perturbational quantities $g(a)$, $\delta_{c}(z_{c})$, $\lambda(z_{c})$,…
We propose a new class of metastable dark energy (DE) phenomenological models in which the DE decay rate does not depend on external parameters such as the scale factor or the curvature of the Universe. Instead, the DE decay rate is assumed…
The dark sector of the Universe is beginning to be clarified step by step. If the dark energy is vacuum energy, then 123 orders are exactly reduced by ordinary physical processes. For many years these unexplained orders were called a crisis…
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…
We derive a model of dark energy which evolves with time via the scale factor. The equation of state $\omega=(1-2\alpha)/(1+2\alpha)$ is studied as a function of a parameter $\alpha$ introduced in this model. In addition to the recent…
The existence of interactions between dark matter and dark energy has been widely studied, since they can fit well the observational data and may provide new physics through such an interaction. In this work we analyze these models and…
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 currently available values and confidence limits for Omega_m0, H_0 and globular cluster ages still indicate that the dark energy that dominates the Universe could also be a form of quintessence or phantom energy. In fact, current…
The dynamical age of the universe depends upon the rate of the expansion of the universe, which explicitly involves the dark energy equation of state parameter $w(z)$. Consequently, the evolution of $w(z)$ has a direct imprint on the age of…
A phenomenological approach is proposed to the problem of universe accelerated expansion and of the dark energy nature. A general class of models is introduced whose energy density depends on the redshift $z$ in such a way that a smooth…
We assume that dark matter and dark energy satisfy the unified equation of state: $p=B(z)\rho$, with $p=p_{dE}$, $\rho=\rho_{dm}+\rho_{dE}$, where the pressure of dark matter $p_{dm}=0$ has been taken into account. A special function…
If dark energy is a form of quintessence driven by a scalar field $\phi$ evolving down a monotonically decreasing potential $V(\phi)$ that passes sufficiently below zero, the universe is destined to undergo a series of smooth transitions.…