scholarly journals COSMIC CONSTRAINT ON RICCI DARK ENERGY MODEL

2009 ◽  
Vol 24 (17) ◽  
pp. 1355-1360 ◽  
Author(s):  
LIXIN XU ◽  
WENBO LI ◽  
JIANBO LU

In this paper, a holographic dark energy model, dubbed Ricci dark energy, is confronted with cosmological observational data from type Ia Supernovae (SN Ia), baryon acoustic oscillations (BAO) and cosmic microwave background (CMB). By using maximum likelihood method, we found that Ricci dark energy model is a viable candidate of dark energy model with the best fit parameters: Ωm0 = 0.34 ± 0.04, α = 0.38 ± 0.03 with 1σ error. Here, α is a dimensionless parameter related to Ricci dark energy ρR and Ricci scalar R, i.e. ρR ∝ αR.

2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Antonella Cid ◽  
Carlos Rodriguez-Benites ◽  
Mauricio Cataldo ◽  
Gonzalo Casanova

AbstractWe perform a Bayesian model selection analysis for interacting scenarios of dark matter and modified holographic Ricci dark energy (MHRDE) with linear interacting terms. We use a combination of some of the latest cosmological data such as type Ia supernovae, cosmic chronometers, the local value of the Hubble constant, baryon acoustic oscillations measurements and cosmic microwave background through the angular scale of the sound horizon at last scattering. We find moderate/strong evidence against all the MHRDE interacting scenarios studied with respect to $$\Lambda $$ Λ CDM when the full joint analysis is considered.


Author(s):  
H. Hossienkhani ◽  
N. Azimi ◽  
H. Yousefi

The impact of anisotropy on the Ricci dark energy cosmologies is investigated where it is assumed that the geometry of the universe is described by Bianchi type I (BI) metric. The main goal is to determine the astrophysical constraints on the model by using the current available data as type Ia supernovae (SNIa), the Baryon Acoustic Oscillation (BAO), and the Hubble parameter [Formula: see text] data. In this regard, a maximum likelihood method is applied to constrain the cosmological parameters. Combining the data, it is found out that the allowed range for the density parameter of the model stands in [Formula: see text]. With the help of the Supernova Legacy Survey (SNLS) sample, we estimate the possible dipole anisotropy of the Ricci dark energy model. Then, by using a standard [Formula: see text] minimization method, it is realized that the transition epoch from early decelerated to current accelerated expansion occurs faster in Ricci dark energy model than [Formula: see text]CDM model. The results indicate that the BI model for the Ricci dark energy is consistent with the observational data.


2011 ◽  
Vol 20 (01) ◽  
pp. 1-16 ◽  
Author(s):  
KOICHI HIRANO ◽  
ZEN KOMIYA

We study the observational constraints on the Phantom Crossing DGP model. We demonstrate that the crossing of the phantom divide does not occur within the framework of the original Dvali–Gabadadze–Porrati (DGP) model or the DGP model developed by Dvali and Turner. By extending their model in the framework of an extra dimension scenario, we study a model that realizes crossing of the phantom divide. We investigate the cosmological constraints obtained from the recent observational data of Type Ia supernovae, cosmic microwave background anisotropies, and baryon acoustic oscillations. The best-fit values of the parameters with 1σ (68%) errors for the Phantom Crossing DGP model are [Formula: see text]. We find that the Phantom Crossing DGP model is more compatible with the observations than the original DGP model or the DGP model developed by Dvali and Turner. Our model can realize late-time acceleration of the universe, similar to that of ΛCDM model, without dark energy due to the effect of DGP gravity. In our model, the crossing of the phantom divide occurs at a redshift of z ~ 0.2.


2013 ◽  
Vol 28 (39) ◽  
pp. 1350171 ◽  
Author(s):  
PENG HUANG ◽  
YONG-CHANG HUANG ◽  
FANG-FANG YUAN

Commonly used boundary conditions in reconstructing f(T) gravity from holographic Ricci dark energy (RDE) model are found to cause some problem, we therefore propose new boundary conditions in this paper. By reconstructing f(T) gravity from the RDE with these new boundary conditions, we show that the new ones are better than the present commonly used ones since they can give the physically expected information, which is lost when the commonly used ones are taken in the reconstruction, of the resulting f(T) theory. Thus, the new boundary conditions proposed here are more suitable for the reconstruction of f(T) gravity.


2015 ◽  
Vol 24 (08) ◽  
pp. 1550059 ◽  
Author(s):  
Jian-bin Chen ◽  
Zhen-qi Liu ◽  
Lili Xing

We investigate the cosmological constraints on the variable modified Chaplygin gas (VMCG) model from the latest observational data: Union2 dataset of Type Ia supernovae (SNIa), the observational Hubble data (OHD), the baryon acoustic oscillations (BAO) and the cosmic microwave background (CMB) data. By using the Markov chain Monte Carlo (MCMC) method, we obtain the mean values of parameters in the flat model: [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]. Furthermore, we investigate the thermodynamical properties of VMCG model at apparent horizon, event horizon and particle horizon respectively.


2006 ◽  
Vol 15 (09) ◽  
pp. 1455-1472 ◽  
Author(s):  
S. ARBABI BIDGOLI ◽  
M. SADEGH MOVAHED ◽  
S. RAHVAR

In this paper we investigate a simple parametrization scheme of the quintessence model given by Wetterich [Phys. Lett. B594, 17 (2004)]. The crucial parameter of this model is the bending parameter b, which is related to the amount of dark energy in the early universe. Using the linear perturbation and the spherical infall approximations, we investigate the evolution of matter density perturbations in the variable dark energy model, and obtain an analytical expression for the growth index f. We show that increasing b leads to less growth of the density contrast δ, and also decreases the growth index. Giving a fitting formula for the growth index at the present time, we verify that the approximation relation [Formula: see text] also holds in this model. To compare predictions of the model with observations, we use the Supernovae type Ia (SNIa) Gold Sample and the parameters of the large scale structure determined by the 2-degree Field Galaxy Redshift Survey (2dFGRS). The best fit values for the model parameters by marginalizing on the remained ones, are [Formula: see text], [Formula: see text] and [Formula: see text] at 1σ confidence level. As a final test we calculate the age of universe for different choices of the free parameters in this model and compare it with the age of old stars and some high redshift objects. Then we show that the predictions of this variable dark energy model are consistent with the age observation of old star and can solve the "age crisis" problem.


Author(s):  
Mariam Bouhmadi-López ◽  
Ahmed Errahmani ◽  
Taoufik Ouali ◽  
Yaser Tavakoli

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