Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Diameter of the Commuting Graph of a Full Matrix Ring over a
  Division Ring   For a division ring D, finite dimensional over its center F, we give a
condiction for the connectedness of the commuting graph of a matrix ring over
$D$. Furthermore, we prove that if the commuting graph is connected, then its
diameter is between four and six.

7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom