Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On gradings of matrix algebras and descent theory
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an