Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonlinear three-wave interaction in marine sediments   Nonlinear interaction of three acoustic waves in a sandy sediment is studied
in the frequency range where there is a considerable wave velocity dispersion.
The possibility of an experimental observation of the generation of a sound
wave by two pump waves propagating at an angle to each other is estimated.

13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph