Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Constraining the nature of the Galactic center black hole Sgr A* with
  present and future observations
16
The categories of this paper are: stat
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics