2012/02/29 by Zhenhui Zhang, Miao Li, Xiao-Dong Li +2
Physics and Astronomy · #astro-ph.CO
paper · pdf · doi:10.1142/s0217732312501155
published as Mod. Phys. Lett. A, Vol. 27, No. 20 (2012) 1250115 · 22 pages, 7 figures, 2 tables, published in MPLA. arXiv admin note: substantial text overlap with arXiv:1106.4116
arxiv created 2012/06/22 · arxiv updated 2012/06/25
In the original holographic dark energy (HDE) model, the dark energy density is proposed to be ρde = 3c2M2plL-2, with c is a dimensionless constant characterizing the properties of the HDE. In this work, we propose the generalized holographic dark energy (GHDE) model by considering the parameter c as a redshift-dependent function c(z). We derive all the physical quantities of the GHDE model analytically, and fit the c(z) by trying four kinds of parametrizations. The cosmological constraints of the c(z) are obtained from the joint analysis of the present SNLS3+BAO+CMB+H0 data. We find that, compared with the original HDE model, the GHDE models can provide a better fit to the data. For example, the GHDE model with JBP-type c(z) can reduce the χ2min of the HDE model by 2.16. We also find that, unlike the original HDE model with a phantom-like behavior in the future, the GHDE models can present many more different possibilities, i.e., it allows the GHDE in the future to be either quintessence like, cosmological constant like, or phantom like, depending on the forms of c(z).