Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: PAAI in the sky : towards a particulate mechanism for Dark Energy and
  concordant Dark Matter
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga