Cosmological Constraints on New Agegraphic Dark Energy

TL;DR

This paper constrains the new agegraphic dark energy model using observational data, finding best-fit parameters that support its viability and potential to address the coincidence problem.

Contribution

It provides the first comprehensive observational constraints on the NADE model, demonstrating its consistency with data and its natural solution to the coincidence problem.

Findings

Best-fit parameter n=2.716 with uncertainties

Derived matter density parameter Ω_m0 ≈ 0.295

Equation of state w_q0 ≈ -0.794

Abstract

In this work, we consider the cosmological constraints on the new agegraphic dark energy (NADE) proposed in arXiv:0708.0884, by using the observational data of type Ia supernovae (SNIa), the shift parameter from cosmic microwave background (CMB) and the baryon acoustic oscillation (BAO) peak from large scale structures (LSS). Thanks to its special analytic features in the radiation-dominated and matter-dominated epochs, NADE is a single-parameter model in practice because once the single model parameter $n$ is given, all other physical quantities of NADE can be determined correspondingly. The joint analysis gives the best-fit value (with $1\sigma$ uncertainty) $n=2.716^{+0.111}_{-0.109}$, and the derived $\Omega_{m0}$, $\Omega_{q0}$ and $w_{q0}$ (with $1\sigma$ uncertainties) are $0.295^{+0.020}_{-0.020}$, $0.705^{+0.020}_{-0.020}$ and $-0.794^{+0.006}_{-0.005}$, respectively. In addition, we find that the coincidence problem could be solved naturally in the NADE model provided that $n$ is of order unity.