Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Spatial bunching of same-charge polarization singularities in
  two-dimensional random vector waves
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th