Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Enigma of B-type Pulsators in the SMC   Since the early nineties it is accepted that the excitation mechanism of
B-type pulsators on the main sequence is due to the opacity peak in the
iron-group elements at $T\approx 200,000$ K. The Fe content plays then a major
role in the excitation of $\beta$ Cep and SPB pulsations. While theoretical
non-adiabatic computations predict no $\beta$ Cep pulsators and only a small
number of SPBs for low metallicity environments such as that of the Magellanic
Clouds (MCs), recent variability surveys of B stars in the SMC have reported
the detection of a significant number of SPB and $\beta$ Cep candidates. Since
the SMC is the metal poorest (Z$\approx$0.001-0.004) of the MCs, it constitutes
an interesting object for investigating the disagreement between theory and
observations. We approach the problem by calling into question some of the
hypotheses made in previous studies: given the different chemical evolution of
the SMC compared with our local galactic environment, is it appropriate to
describe the chemical composition of SMC B stars by scaling the solar mixture
to lower $Z$? Is that composition uniform in space and time? In this paper we
present the results of a stability analysis of B-type stellar models computed
with a revised chemical composition and metallicity specific to the SMC.

10
The categories of this paper are: q-bio
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The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
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The categories of this paper are: nlin
29
The categories of this paper are: funct-an
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The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
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The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-th
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The categories of this paper are: adap-org
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The categories of this paper are: comp-gas