Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Constraints on the radial mass distribution of dark matter halos from
  rotation curves   Stars have mass; halos lack cusps.

2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat