Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A property of conformally Hamiltonian vector fields; application to the
  Kepler problem
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph