Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The gravitational field of a cube   Large astronomical objects such as stars or planets, produce approximately
spherical shapes due to the large gravitational forces, and if the object is
rotating rapidly, it becomes an oblate spheroid. In juxtaposition to this, we
conduct a thought experiment regarding the properties of a planet being in the
form of a perfect cube. We firstly calculate the gravitational potential and
from the equipotentials, we deduce the shape of the lakes that would form on
the surface of such an object. We then consider the formation of orbits around
such objects both with a static and a rotating cube. A possible practical
application of these results is that, because cuboid objects can be easily
stacked together, we can calculate the field of more complicated shapes, using
the principle of superposition, by simply adding the field from a set of
component shapes.

2
The categories of this paper are: math
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio