A global fit study on the new agegraphic dark energy model
  We perform a global fit study on the new agegraphic dark energy (NADE) model
in a non-flat universe by using the MCMC method with the full CMB power spectra
data from the WMAP 7-yr observations, the SNIa data from Union2.1 sample, BAO
data from SDSS DR7 and WiggleZ Dark Energy Survey, and the latest measurements
of $H_0$ from HST. We find that the value of $\Omega_{k0}$ is greater than 0 at
least at the 3$\sigma$ confidence levels (CLs), which implies that the NADE
model distinctly favors an open universe. Besides, our results show that the
value of the key parameter of NADE model,
$n=2.673^{+0.053+0.127+0.199}_{-0.077-0.151-0.222}$, at the 1--3$\sigma$ CLs,
where its best-fit value is significantly smaller than those obtained in
previous works. We find that the reason leading to such a change comes from the
different SNIa samples used. Our further test indicates that there is a
distinct tension between the Union2 sample of SNIa and other observations, and
the tension will be relieved once the Union2 sample is replaced by the Union2.1
sample. So, the new constraint result of the NADE model obtained in this work
is more reasonable than before.
