Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Filtrations of free groups as intersections   For several natural filtrations of a free group S we express the n-th term of
the filtration as the intersection of all kernels of homomorphisms from S to
certain groups of upper-triangular unipotent matrices. This generalizes a
classical result of Grun for the lower central filtration. In particular, we do
this for the n-th term in the lower p-central filtration of S.

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The categories of this paper are: plasm-ph
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The categories of this paper are: econ
0
The categories of this paper are: hep-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: funct-an
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The categories of this paper are: alg-geom
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The categories of this paper are: patt-sol
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-th
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The categories of this paper are: comp-gas
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The categories of this paper are: nucl-th
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The categories of this paper are: cond-mat
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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: chao-dyn
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The categories of this paper are: eess