Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Travelling solitons in the parametrically driven nonlinear Schroedinger
  equation   We show that the parametrically driven nonlinear Schroedinger equation has
wide classes of travelling soliton solutions, some of which are stable. For
small driving strengths nonpropogating and moving solitons co-exist while
strongly forced solitons can only be stably when moving sufficiently fast.

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The categories of this paper are: eess
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The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
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The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
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The categories of this paper are: acc-phys
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The categories of this paper are: econ
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
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The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: funct-an
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The categories of this paper are: solv-int