Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Group Action Method and Radial Projection   The group action methods have been playing an important role in recent
studies about the configuration problems inside a compact set $E$ in Euclidean
spaces with given Hausdorff dimension. In this paper, we further explore the
group action methods to study the radial projection problems for Salem sets.

5
The categories of this paper are: gr-qc
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The categories of this paper are: q-fin
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
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The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: adap-org
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The categories of this paper are: econ
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The categories of this paper are: stat
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The categories of this paper are: astro-ph
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The categories of this paper are: eess
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The categories of this paper are: nlin
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The categories of this paper are: nucl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-th