Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quasi-periodic solutions for differential equations with an
  elliptic-type degenerate equilibrium point under small perturbations   This work focuses on the existence of quasi-periodic solutions for ordinary
and delay differential equations (ODEs and DDEs for short) with an
elliptic-type degenerate equilibrium point under quasi-periodic perturbations.
We prove that under appropriate hypotheses there exist quasi-periodic solutions
for perturbed ODEs and DDEs near the equilibrium point for most parameter
values, then apply these results to the delayed van der Pol's oscillator with
zero-Hopf singularity.

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The categories of this paper are: astro-ph
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The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
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The categories of this paper are: eess
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
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The categories of this paper are: econ
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The categories of this paper are: adap-org
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The categories of this paper are: plasm-ph
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The categories of this paper are: solv-int
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The categories of this paper are: mtrl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: chao-dyn