Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: U(1)-invariant membranes: the geometric formulation, Abel and pendulum
  differential equations
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con