Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Relic gravitational waves produced after preheating   We show that gravitational radiation is produced quite efficiently in
interactions of classical waves created by resonant decay of a coherently
oscillating field. For simple models of chaotic inflation in which the inflaton
interacts with another scalar field, we find that today's ratio of energy
density in gravitational waves per octave to the critical density of the
universe can be as large as 10^{-12} at the maximal wavelength of order 10^{5}
cm. In the pure $\lambda\phi^4$ model, the maximal today's wavelength of
gravitational waves produced by this mechanism is of order 10^6 cm, close to
the upper bound of operational LIGO and TIGA frequencies. The energy density of
waves in this model, though, is likely to be well below the sensitivity of LIGO
or TIGA at such frequencies. We discuss possibility that in other inflationary
models interaction of classical waves can lead to an even stronger
gravitational radiation background.

25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
26
The categories of this paper are: bayes-an