Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Polynomial decay of correlations for nonpositively curved surfaces   We prove polynomial decay of correlations for geodesic flows on a class of
nonpositively curved surfaces where zero curvature only occurs along one closed
geodesic. We also prove that various statistical limit laws, including the
central limit theorem, are satisfied by this class of geodesic flows.

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: cmp-lg
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-fin
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The categories of this paper are: atom-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: econ
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The categories of this paper are: dg-ga
3
The categories of this paper are: physics
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The categories of this paper are: bayes-an
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: eess