Cosmological Constraint and Analysis on Holographic Dark Energy Model Characterized by the Conformal-age-like Length

Abstract

We present a best-fit analysis on the single-parameter holographic dark energy model characterized by the conformal-age-like length, $L=\frac{1}{a^4(t)}{\int }_0^{t}d{t}^{\prime }{a}^3(t^{\prime })$. Based on the Union2 compilation of 557 supernova Ia data, the baryon acoustic oscillation results from the SDSS DR7 and the cosmic microwave background radiation data from the WMAP7, we show that the model gives the minimal ${\chi }_{min}^2=546.273$, which is comparable to ${\chi }_{\Lambda \mathrm{CDM}}^2=544.616$ for the $\Lambda$CDM model. The single parameter $d$ concerned in the model is found to be $d=0.232\pm 0.006\pm 0.009$. Since the fractional density of dark energy ${\Omega }_{de}\sim d^2{a}^2$ at $a\ll 1$, the fraction of dark energy is naturally negligible in the early universe, ${\Omega }_{de}\ll 1$ at $a\ll 1$. The resulting constraints on the present fractional energy density of matter and the equation of state are $Ω_{m0}=0.286^{+0.019}_{-0.018}^{+0.032}_{-0.028}$ and $w_{de0}=-1.240^{+0.027}_{-0.027}^{+0.045}_{-0.044}$ respectively. The model leads to a slightly larger fraction of matter comparing to the $\Lambda$CDM model. We also provide a systematic analysis on the cosmic evolutions of the fractional energy density of dark energy, the equation of state of dark energy, the deceleration parameter and the statefinder. It is noticed that the equation of state crosses from $w_{de}>-1$ to $w_{de}<-1$, the universe transits from decelerated expansion ($q>0$) to accelerated expansion ($q<0$) recently, and the statefinder may serve as a sensitive diagnostic to distinguish the CHDE model with the $\Lambda$CDM model.

17 pages, 5 figures, minor changes for the fitting data, references added

References in corpus (18)

• Dynamics of dark energy
• Spectra and Light Curves of Six Type Ia Supernovae at 0.511 < z < 1.12 and the Union2 Compilation
• A Dark Energy Model Characterized by the Age of the Universe
• A New Model of Agegraphic Dark Energy
• A Holographic Dark Energy Model from Ricci Scalar Curvature
• Infrared cut-off proposal for the Holographic density
• New infrared cut-off for the holographic scalar fields models of dark energy
• Interacting holographic dark energy model in non-flat universe
• Holographic dark energy with varying gravitational constant
• A Tracker Solution for a Holographic Dark Energy Model
• Cosmological implications of Karolyhazy uncertainty relation
• Space-time in light of Karolyhazy uncertainty relation
• Inflation with Holographic Dark Energy
• Observational Constraints on Exponential Gravity
• Holographic Ricci dark energy in Randall-Sundrum braneworld: Avoidance of big rip and steady state future
• From spacetime foam to holographic foam cosmology
• Holographic Dark Energy Characterized by the Total Comoving Horizon and Insights to Cosmological Constant and Coincidence Problem
• Holographic Dark Energy Model Characterized by the Conformal-age-like Length

Cited by in corpus (4)

• Holographic Dark Energy
• Holographic dark energy in a universe with spatial curvature and massive neutrinos: a full Markov Chain Monte Carlo exploration
• Holographic energy density, dark energy sound speed, and tensions in cosmological parameters: $H_0$ and $S_8$
• (m,n)-type holographic dark energy models