Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A new cosmic microwave background constraint to primordial gravitational
  waves
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
19
The categories of this paper are: eess
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con