1303.0384 (Ming-Jian Zhang et al.)

Cosmological constraints on holographic dark energy models under the energy conditions    [PDF]

Ming-Jian Zhang, Zhong-Xu Zhai, Cong Ma, Tong-Jie Zhang

We study the holographic and agegraphic dark energy models with the observational Hubble parameter data (OHD), the Union2 data set of type Ia supernovae (SNIa), and the energy conditions. Scenarios of dark energy are distinguished by the cut-off of cosmic age, conformal time, and event horizon. The joint constraint from observational data gives $\Omega_{m0} = 0.22 \pm 0.03$, and $c > 5.92$ for age cut-off, $\Omega_{m0}=0.2 \pm 0.03$, and $c > 6.43$ for conformal time cut-off, and $\Omega_{m0} = 0.22^{+0.04}_{-0.05}$, and $c=0.84_{-0.12}^{+0.14}$ for event horizon cut-off. Our results show that the two former models finally reduce to $\Lambda$CDM model, but the latter is different from $\Lambda$CDM model. Comparing with the energy conditions, we find that SEC is fulfilled at redshift $z \gtrsim 0.3$ with $1\sigma$ confidence level, and $z \gtrsim 0.5$ with $3\sigma$ confidence level, which is well consistent with the result reported by \citet{wu2011reconstructing}. Notably the null energy condition is showed to closely track the data constraints, thereby distinguishes itself from other energy conditions.

View original: http://arxiv.org/abs/1303.0384