Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thin discs, thick discs and transition zones   Accretion onto a compact object must occur through a disc when the material
has some initial angular momentum. Thin discs and the thicker low radiative
efficiency accretion flows are solutions to this problem that have been widely
studied and applied. This is an introduction to these accretion flows within
the context of X-ray binaries and cataclysmic variables.

30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat