Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Traveling and standing waves in coupled pendula and Newton's cradle   The existence of traveling and standing waves is investigated for chains of
coupled pendula with periodic boundary conditions. The results are proven by
applying topological methods to subspaces of symmetric solutions. The main
advantage of this approach comes from the fact that only properties of the
linearized forces are required. This allows to cover a wide range of models
such as Newton's cradle, the Fermi-Pasta-Ulam lattice and the Toda lattice.

11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg