Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: First observational constraints on tensor non-Gaussianity sourced by
  primordial magnetic fields from cosmic microwave background
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci