Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Scattering by a draining bathtub vortex   We present an analysis of scattering by a fluid-mechanical `black hole
analogue', known as the draining bathtub vortex: a two-dimensional flow which
possesses both a sonic horizon and an ergoregion. We consider the scattering of
a plane wave of fixed frequency impinging upon the vortex. At low frequency, we
encounter a modified Aharonov-Bohm effect. At high frequencies, we observe
regular `orbiting' oscillations in the scattering length, due to interference
between contra-orbiting rays. We present approximate formulae for both effects,
and a selection of numerical results obtained by summing partial-wave series.
Finally, we examine interference patterns in the vicinity of the vortex, and
highlight the prospects for experimental investigation.

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The categories of this paper are: cmp-lg
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
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The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess