Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Reconstructing the nature of the first cosmic sources from the
  anisotropic 21-cm signal
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics