Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Further evidence for a variable fine-structure constant from Keck/HIRES
  QSO absorption spectra
18
The categories of this paper are: econ
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph