Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the stability of periodic orbits for differential systems in
  $\mathbb{R}^n$
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org