Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Synchronous motion of two vertically excited planar elastic pendula   The dynamics of two planar elastic pendula mounted on the horizontally
excited platform have been studied. We give evidence that the pendula can
exhibit synchronous oscillatory and rotation motion and show that stable
in-phase and anti-phase synchronous states always co-exist. The complete
bifurcational scenario leading from synchronous to asynchronous motion is
shown. We argue that our results are robust as they exist in the wide range of
the system parameters.

6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol