Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Creation of the Nonconformal Scalar Particles in Nonstationary Metric   The nonconformal scalar field is considered in N-dimensional space-time with
metric which includes, in particular, the cases of nonhomogeneous spaces and
anisotropic spaces of Bianchi type-I. The modified Hamiltonian is constructed.
Under the diagonalization of it the energy of quasiparticles is equal to the
oscillator frequency of the wave equation. The density of particles created by
nonstationary metric is investigated. It is shown that the densities of
conformal and nonconformal particles created in Friedmann radiative-dominant
Universe coincide.

7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th