Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectrum of Gravitational Waves in Krein Space Quantization   The main goal of this paper is to derive the primordial power spectrum for
the scalar perturbations generated as a result of quantum fluctuations during
an inflationary pe- riod by an alternative approach of field quantization[1-3].
Formulas are derived for the gravitational waves, special cases of which
include power law inflation and inflation in the slow roll approximation, in
Krein space quantization.

30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
9
The categories of this paper are: nlin