Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Superexpansion as a possible probe of accretion in 4U 1820-30
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th