Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum Fluctuations for Gravitational Impulsive Waves   Quantum fluctuations for a massless scalar field in the background metric of
spherical impulsive gravitational waves through Minkowski and de Sitter spaces
are investigated. It is shown that there exist finite fluctuations for de
Sitter space.

2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an