Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Statistical characteristics of observed Ly-$\alpha$ forest and the shape
  of initial power spectrum
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin