Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: No C+ emission from the z=3.137 damped Lyman-alpha absorber towards
  PC1643+4631A
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
2
The categories of this paper are: math
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat