Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Stability of low-dimensional bushes of vibrational modes in the
  Fermi-Pasta-Ulam chains   Bushes of normal modes represent the exact excitations in nonlinear physical
systems with discrete symmetries [Physica D117 (1998) 43]. The present paper is
the continuation of our previous paper [Physica D166 (2002) 208], where these
dynamical objects of a new type were discussed for the monoatomic nonlinear
chains. Here, we develop a simple crystallographic method for finding bushes in
nonlinear chains and investigate stability of one-dimensional and
two-dimensional vibrational bushes for both FPU-alpha and FPU-beta models, in
particular, of those revealed recently in [Physica D175 (2003) 31].

18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat