Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Gravitational Scattering Amplitudes and Closed String Field Theory in
  the Proper-Time Gauge
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph