Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Implications of JLA data for $k-$essence model of dark energy with given
  equation of state   We investigated implications of recently released `Joint Light-curve
Analysis' (JLA) supernova Ia (SNe Ia) data for dark energy models with time
varying equation of state of dark energy, usually expressed as $w(z)$ in terms
of variation with corresponding redshift $z$. From a comprehensive analysis of
the JLA data, we obtain the observational constraints on the different
functional forms of $w(z)$, corresponding to different varying dark energy
models often considered in literature, \textit{viz.} CPL, JBP, BA and
Logarithmic models. The constraints are expressed in terms of parameters ($w_a,
w_b$) appearing in the chosen functional form for $w(z)$, corresponding to each
of the above mentioned models. Realising dark energy with varying equation of
state in terms of a homogeneous scalar field $\phi$, with its dynamics driven
by a $k-$essence Lagrangian $L=VF(X)$ with a constant potential $V$ and a
dynamical term $F(X)$ with $X=(1/2)\nabla^\mu\phi\nabla_\mu\phi$ we
reconstructed form of the function $F(X)$. This reconstruction has been
performed for different varying dark energy models at best-fit values of
parameters ($w_a, w_b$) obtained from analysis of JLA data. In the context of
$k-$essence model, we also investigate the variation of adiabatic sound speed
squared, $c_s^2(z)$, and obtained the domains in ($w_a, w_b$) parameter space
corresponding to the physical bound $ c_s^2>0$ implying stability of density
perturbations.

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The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
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The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs