Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A note on some group $C^*$-algebras which are quasi-directly finite
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
1
The categories of this paper are: cs