Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Unique Fock quantization of a massive fermion field in a cosmological
  scenario
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol