Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Inertial modes in stratified rotating neutron stars : An evolutionary
  description   With (non-barotropic) equations of state valid even when the neutron, proton
and electron content of neutron star cores is not in beta equilibrium, we study
inertial and composition gravity modes of relativistic rotating neutron stars.
We solve the relativistic Euler equations in the time domain with a three
dimensional numerical code based on spectral methods, in the slow rotation,
relativistic Cowling and anelastic approximations. Principally, after a short
description of the gravity modes due to smooth composition gradients, we focus
our analysis on the question of how the inertial modes are affected by
non-barotropicity of the nuclear matter. In our study, the deviation with
respect to barotropicity results from the frozen composition of non-superfluid
matter composed of neutrons, protons and electrons, when beta equilibrium is
broken by millisecond oscillations. We show that already for moderatly fast
rotating stars the increasing coupling between polar and axial modes makes
those two cases less different than for very slowly rotating stars. In
addition, as we directly solve the Euler equations, without coupling only a few
number of spherical harmonics, we always found, for the models that we use, a
discrete spectrum for the $l = m = 2$ inertial mode. Finally, we find that, for
non-barotropic stars, the frequency of this mode, which is our main focus,
decreases in a non-negligible way, whereas the time dependence of the energy
transfer between polar and axial modes is substantially different due to the
existence of low-frequencies gravity modes.

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The categories of this paper are: math
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
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The categories of this paper are: cond-mat
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The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn