Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The demographics of neutron star - white dwarf mergers: rates,
  delay-time distributions and progenitors
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys