Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Poisson structure and Action-Angle variables for the Camassa-Holm
  equation   The Poisson brackets for the scattering data of the Camassa-Holm equation are
computed. Consequently, the action-angle variables are expressed in terms of
the scattering data.

23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an