Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the Inference of the Cosmic Ray Ionization Rate $\zeta$ from the
  HCO$^+$-to-DCO$^+$ Abundance Ratio: The Effect of Nuclear Spin
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc