Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Orbits of Darboux groupoid for hyperbolic operators of order three   Darboux transformations are viewed as morphisms in a Darboux category.
Darboux transformations of type I which we defined previously, make an
important subgroupoid consists of Darboux transformations of type I. We
describe the orbits of this subgroupoid for hyperbolic operators of order
three.
  We consider the algebras of differential invariants for our operators. In
particular, we show that the Darboux transformations of this class can be
lifted to transformations of differential invariants (which we calculate
explicitly).

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The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an