Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Flat rotational curves without dark matter   We consider the singular configurations of gravitating gas [1] which could be
used as a model for disk galaxies. The simplest steady configuration, which
corresponds to rotation of stars around center gives flat rotational curve,
provided the density distrubution has a tail, decaying as 1/r. This result
based exclusively on Newtonian gravity and does not involve dark matter.

8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc