Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Studying the normal-fluid flow in Helium-II using metastable helium
  molecules
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin