Related papers: Dark energy with polytropic equation of state
The possibility of constraining the parameters of scalar field dark energy with barotropic equation of state using different available datasets is discussed. It has been found that the initial value of dark energy equation of state…
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…
Dark energy equation of state can be effectively described by that of a barotropic fluid. The barotropic fluid model describes the background evolution and the functional form of the equation of state parameter is well constrained by the…
We propose a completely new parametrisation of the dark energy equation of state, which uses the dark energy density, $\Omega_e$ as a cosmic clock. We expand the equation of state in a series of orthogonal polynomials, with $\Omega_e$ as…
Entropy bounds render quantum corrections to the cosmological constant $\Lambda$ finite. Under certain assumptions, the natural value of $\Lambda$ is of order the observed dark energy density $\sim 10^{-10} {\rm eV}^4$, thereby resolving…
Since the discovery of the accelerated expansion of the universe, it was necessary to introduce a new component of matter distribution called dark energy. The standard cosmological model considers isotropy of the pressure and assumes an…
There are various cosmological models with polytropic equation of state associated to dark energy. Polytropic EoS has important applications in astrophysics, therefore a study of it on cosmological framework continues to be interesting.…
The thermodynamic properties of dark energy fluids described by an equation of state parameter $\omega=p/\rho$ are rediscussed in the context of FRW type geometries. Contrarily to previous claims, it is argued here that the phantom regime…
We investigate a model of the interacting holographic dark energy with cold dark matter (CDM). If the holographic energy density decays into CDM, we find two types of the effective equation of state. In this case we have to use the…
We explore the possibility that the dark energy is due to a potential of a scalar field and that the magnitude and the slope of this potential in our part of the universe are largely determined by anthropic selection effects. We find that,…
In the contemporary Cosmology, dark energy is modeled as a perfect fluid, having a very simple equation of state: pressure is proportional to dark energy density. As an alternative, I propose a more complex equation of state, with pressure…
We suggest that vacuum entanglement energy associated with the entanglement entropy of the universe is the origin of dark energy. The observed properties of dark energy can be explained by using the nature of entanglement energy without…
Our ignorance of the dark energy is generally described by a two-parameter equation of state. In these approaches a particular {\it ad hoc} functional form is assumed, and only two independent parameters are incorporated. We propose a…
The interacting polytropic gas dark energy model is investigated from the viewpoint of statefinder diagnostic tool and $w-w^{\prime}$ analysis. The dependency of the statefinder parameters on the parameter of the model as well as the…
Some cosmological scenarios with bulk viscosity for the dark energy fluid are considered. Based on some considerations related to hydrodynamics, two different equations of state for dark energy are assumed, leading to power-law and…
From recent CMB and Large Scale Structure observations the value of the equation of state of dark energy, assuming it to be constant in time, is constrained to be -1.3<w<-0.7 at the 95% confidence level: consistent with dark energy being a…
The authors of the paper ''On Anisotropic Dark Energy Stars'', arXiv:0803.2508 [gr-qc], consider the equations of state $p_r=\omega \rho$ and $p_t=\omega \rho$, ignoring the fact that this implies an isotropic pressure, which places strict…
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…
It is well known that phantom energy, which is characterized by the equation of state $p=\omega\rho$, $\omega <-1$, can support Morris-Thorne wormholes since it leads to a violation of the null energy condition. The purpose of this note is…
We propose a parameterized equation of state for dark energy and perform observational tests with the Hubble parameter measurements, the Pantheon supernova sample, baryon acoustic oscillations, and DESI DR2 data. We obtain the best-fit…