Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Counting problem on wind-tree models   We study periodic wind-tree models, billiards in the plane endowed with
$\mathbb{Z}^2$-periodically located identical connected symmetric right-angled
obstacles. We show asymptotic formulas for the number of (isotopy classes of)
closed billiard trajectories (up to $\mathbb{Z}^2$-translations) on the
wind-tree billiard. We also compute explicitly the associated Siegel-Veech
constant for generic wind-tree billiards depending on the number of corners on
the obstacle.

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The categories of this paper are: nucl-th
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The categories of this paper are: comp-gas
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The categories of this paper are: math-ph
3
The categories of this paper are: physics
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The categories of this paper are: adap-org
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The categories of this paper are: cmp-lg
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The categories of this paper are: cs
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The categories of this paper are: acc-phys
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The categories of this paper are: eess
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The categories of this paper are: supr-con
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The categories of this paper are: plasm-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: stat
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The categories of this paper are: q-bio
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The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph