Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Relativistic effects in galaxy clustering in a parametrized
  post-Friedmann universe
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
2
The categories of this paper are: math
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess