Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Improved cosmological constraints on the curvature and equation of state
  of dark energy   We apply the Constitution compilation of 397 supernova Ia, the baryon
acoustic oscillation measurements including the $A$ parameter, the distance
ratio and the radial data, the five-year Wilkinson microwave anisotropy probe
and the Hubble parameter data to study the geometry of the universe and the
property of dark energy by using the popular Chevallier-Polarski-Linder and
Jassal-Bagla-Padmanabhan parameterizations. We compare the simple $\chi^2$
method of joined contour estimation and the Monte Carlo Markov chain method,
and find that it is necessary to make the marginalized analysis on the error
estimation. The probabilities of $\Omega_k$ and $w_a$ in the
Chevallier-Polarski-Linder model are skew distributions, and the marginalized
$1\sigma$ errors are $\Omega_m=0.279^{+0.015}_{-0.008}$,
$\Omega_k=0.005^{+0.006}_{-0.011}$, $w_0=-1.05^{+0.23}_{-0.06}$, and
$w_a=0.5^{+0.3}_{-1.5}$. For the Jassal-Bagla-Padmanabhan model, the
marginalized $1\sigma$ errors are $\Omega_m=0.281^{+0.015}_{-0.01}$,
$\Omega_k=0.000^{+0.007}_{-0.006}$, $w_0=-0.96^{+0.25}_{-0.18}$, and
$w_a=-0.6^{+1.9}_{-1.6}$. The equation of state parameter $w(z)$ of dark energy
is negative in the redshift range $0\le z\le 2$ at more than $3\sigma$ level.
The flat $\Lambda$CDM model is consistent with the current observational data
at the $1\sigma$ level.

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The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
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The categories of this paper are: quant-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: eess
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
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The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: cs