Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ground state of nonlinear Schrodinger systems with saturable
  nonlinearity   We prove the existence of ground state in a multidimensional nonlinear
Schrodinger model of paraxial beam propagation in isotropic local media with
saturable nonlinearity. Such ground states exist in the form of bright
counterpropagating solitons. From the proof, a general threshold condition on
the beam coupling constant for the existence of such fundamental solitons
follows.

3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas