Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: CMB Constraints on WIMP Annihilation: Energy Absorption During the
  Recombination Epoch
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas