Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Affine Hopf fibration   An affine Hopf fibration is a fibration of n-dimensional real affine space by
p-dimensional pairwise skew affine subspaces. An example is a fibration of
3-space by pairwise skew lines, the result of the central projection of the
classical Hopf fibration of 3-sphere. In this expository article, we describe
the solution of the following problem: for which values of n and p does an
affine Hopf fibration exist? The answer is given in terms of the Hurwitz-Radon
function.

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The categories of this paper are: chem-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: mtrl-th
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The categories of this paper are: eess
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The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
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The categories of this paper are: nucl-ex
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The categories of this paper are: gr-qc
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-lat
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The categories of this paper are: comp-gas
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The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
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The categories of this paper are: funct-an