Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The matrix Kadomtsev--Petviashvili equation as a source of integrable
  nonlinear equations   A new integrable class of Davey--Stewartson type systems of nonlinear partial
differential equations (NPDEs) in 2+1 dimensions is derived from the matrix
Kadomtsev--Petviashvili equation by means of an asymptotically exact nonlinear
reduction method based on Fourier expansion and spatio-temporal rescaling. The
integrability by the inverse scattering method is explicitly demonstrated, by
applying the reduction technique also to the Lax pair of the starting matrix
equation and thereby obtaining the Lax pair for the new class of systems of
equations. The characteristics of the reduction method suggest that the new
systems are likely to be of applicative relevance. A reduction to a system of
two interacting complex fields is briefly described.

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The categories of this paper are: nucl-ex
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The categories of this paper are: plasm-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-th
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The categories of this paper are: hep-lat
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The categories of this paper are: solv-int
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The categories of this paper are: chem-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: math-ph
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The categories of this paper are: eess
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The categories of this paper are: adap-org
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The categories of this paper are: q-fin
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The categories of this paper are: chao-dyn
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The categories of this paper are: quant-ph
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The categories of this paper are: alg-geom