Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Infinite ergodic index of the ehrenfest wind-tree model   The set of all possible configurations of the Ehrenfest wind-tree model
endowed with the Hausdorff topology is a compact metric space. For a typical
configuration we show that the wind-tree dynamics has infinite ergodic index in
almost every direction. In particular some ergodic theorems can be applied to
show that if we start with a large number of initially parallel particles their
directions decorrelate as the dynamics evolve answering the question posed by
the Ehrenfests.

31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
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The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
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The categories of this paper are: solv-int
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The categories of this paper are: mtrl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: q-fin
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex