Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Water-wave gap solitons: An approximate theory and accurate numerical
  experiments   It is demonstrated that a standard coupled-mode theory can successfully
describe weakly-nonlinear gravity water waves in Bragg resonance with a
periodic one-dimensional topography. Analytical solutions for gap solitons
provided by this theory are in a reasonable agreement with accurate numerical
simulations of exact equations of motion for ideal planar potential
free-surface flows, even for strongly nonlinear waves. In numerical
experiments, self-localized groups of nearly standing water waves can exist up
to hundreds of wave periods. Generalizations of the model to the
three-dimensional case are also derived.

19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex