Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gravity waves on modulated flows downstream from an obstacle: The
  transcritical case   Periodic spatial variations of some parameter arise in analogue gravity
experiments aimed at detecting the analogue version of the Hawking effect in a
white hole flow. Having the same spatial periodicity as low-frequency
dispersive modes, they can induce resonances which significantly modify the
scattering coefficients. This has been shown numerically in a previous work [X.
Busch et al., Phys. Rev. D 90, 105005 (2014)], but the precise dependence of
the low-frequency effective temperature on the amplitude and length of the
undulation remains elusive. In this article, using the Korteweg-de Vries
equation, we explicitly compute this dependence in the small-amplitude limit
and find three regimes of "short", "intermediate" and "long" undulations
showing different scaling laws. In the latter, the effective temperature is
completely determined by the properties of the undulation, independently of the
surface gravity of the analogue white hole flow. These results are extended to
a more realistic hydrodynamical model in an appendix.

16
The categories of this paper are: stat
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn