Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Variational Approach to Complicated Similarity Solutions of Higher-Order
  Nonlinear PDEs. II   Some higher-order quasilinear parabolic, hyperbolic, and nonlinear dispersion
equations are shown to admit various blow-up, extinction, and travelling wave
solutions, which reduce to variational problems admitting countable families of
compactly supported solutions.

23
The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat