Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Stability and instability results for standing waves of quasi-linear
  Schr\"odinger equations   We study a class of quasi-linear Schr\"odinger equations arising in the
theory of superfluid film in plasma physics. First, using gauge transforms and
a derivation process we solve, under some regularity assumptions, the Cauchy
problem. Then, by means of variational methods, we study the existence, the
orbital stability and instability of standing waves which minimize some
associated energy.

17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph