相关论文: Barotropic fluid compatible parametrizations of da…
On the basis of homogeneous and isotropic Friedmann-Lemaitre-Robertson-Walker (FLRW) geometry, solutions to the issues of cosmic acceleration and dark energy are being put forth within the context of $f\left( Q\right)$ gravity. We take into…
In this article, we investigate a new parametrization of the dark energy equation of state (EoS) with a single parameter for a barotropic fluid that deviates from the standard $\Lambda$CDM cosmology. We derive observational constraints on…
Determining the mechanism behind the current cosmic acceleration constitutes a major question nowadays in theoretical physics. If the dark energy route is taken, this problem may potentially bring to light new insights not only in Cosmology…
In this work, FRW universe filled with dark matter (perfect fluid with negligible pressure) along with dark energy in the background of Galileon gravity is considered. Four dark energy models with different EoS parametrizations have been…
In this paper, we quantify the non-linear effects from $k$-essence dark energy through an effective parameter $\mu$ that encodes the additional contribution of a dark energy fluid or a modification of gravity to the Poisson equation. This…
A unification of dark matter and dark energy in terms of a logotropic perfect dark fluid has recently been proposed, where deviations with respect to the standard $\Lambda {\rm CDM}$ model are dependent on a single parameter $B$. In this…
We consider theories with a nontrivial coupling between the matter and dark energy sectors. We describe a small scale instability that can occur in such models when the coupling is strong compared to gravity, generalizing and correcting…
The distribution of dark energy density in the vicinity of compact static objects is analyzed. Dark energy is assumed to be in the form of a scalar field with three parameters: the background density, the equation of state parameter and the…
We develop here a relatively simple description of dark energy based on the dynamics of non-minimally coupled to gravity phantom scalar field which, in limit, corresponds to cosmological constant. The dark energy equation of state, obtained…
We have studied constraints on the equation of state, $w$, and speed of sound, c_s, of the dark energy from a joint analysis of data from the cosmic microwave background, large scale structure and type-Ia supernovae. We find that current…
In models where dark matter and dark energy interact non-minimally, the total amount of matter in a fixed comoving volume may vary from the time of recombination to the present time due to energy transfer between the two components. This…
We investigate the agegraphic dark energy models which were recently proposed to explain the dark energy-dominated universe. For this purpose, we calculate their equation of states and squared speeds of sound. We find that the squared speed…
A data-driven approach to elucidating the nature of the dark energy, in the form of a joint analysis of a full set of cosmological parameters, utilizing all available observational data is proposed. A parameterization of a generalized dark…
The evolution of the dark energy parameter within the scope of a spatially homogeneous and isotropic Friedmann-Robertson-Walker (FRW) model filled with perfect fluid and dark energy components is studied by generalizing the recent results…
We apply in this paper the statefinder parameters to the interacting phantom energy with dark matter. There are two kinds of scaling solutions in this model. It is found that the evolving trajectories of these two scaling solutions in the…
As is known above 90% of the energy content in Universe is made of unknown dark component. Usually this dark fluid is separated into two parts: dark matter and dark energy. However, it may be a mixture of these two energy components, or…
In this work, we analyze a scalar field model which gives rise to stable bound states in field space characterized by nonzero motion that breaks the underlying time translation symmetry of its Hamiltonian, known as time crystals. We…
In this paper, a unified dark fluid with constant adiabatic sound speed is decomposed into cold dark matter interacting with vacuum energy. Based on Markov chain Monte Carlo method, we constrain this model by jointing the geometry and…
We consider spherically symmetric inhomogeneous pressure Stephani universes, the center of symmetry being our location. The main feature of these models is that comoving observers do not follow geodesics. In particular, comoving perfect…
We consider a model that charged static spherically-symmetric black hole is surrounded by dark fluid with nonlinear equation of state $p_d=-B/\rho_d$. We find that the energy density of the dark fluid can be characterized by two parameters.…