Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Noncommutative Extension of Gravity   The commutative algebra of functions on a manifold is extended to a
noncommutative algebra by considering its tensor product with the algebra of
nxn complex matrices. Noncommutative geometry is used to formulate an extension
of the Einstein-Hilbert action. The result is shown to be equivalent to the
usual Kaluza-Klein theory with the manifold SUn as an internal space, in a
truncated approximation.

20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
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
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess