Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The effects of an extra U(1) axial condensate on the radiative decay
  eta' --> gamma gamma at finite temperature
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas