Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Testing stellar population synthesis models with Sloan Digital Sky
  Survey colors of M31's globular clusters
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th