Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Weak bi-center and critical period bifurcations of a $Z_2$-Equivariant
  quintic system   With the help of computer algebra system-\textsc{Mathematica}, this paper
considers the weak center problem and local critical periods for bi-center of a
$Z_2$-Equivariant quintic system with eight parameters. The order of weak
bi-center is identified and the exact maximum number of bifurcation of critical
periods generated from the bi-center is given via the combination of symbolic
calculation and numerical analysis.

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The categories of this paper are: cs
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
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The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
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The categories of this paper are: nucl-ex
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The categories of this paper are: solv-int
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The categories of this paper are: econ
32
The categories of this paper are: atom-ph