Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Causal perturbation theory in general FRW cosmologies I: energy momentum
  conservation and matching conditions
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex