Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Geometric Constructions Underlying Relativistic Description of Spin on
  the Base of Non-Grassmann Vector-Like Variable   Basic notions of Dirac theory of constrained systems have their analogs in
differential geometry. Combination of the two approaches gives more clear
understanding of both classical and quantum mechanics, when we deal with a
model with complicated structure of constraints. In this work we describe and
discuss the spin fiber bundle which appeared in various mechanical models where
spin is described by vector-like variable.

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The categories of this paper are: hep-ex
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The categories of this paper are: adap-org
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The categories of this paper are: cmp-lg
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The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
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The categories of this paper are: nlin
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The categories of this paper are: q-bio
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The categories of this paper are: mtrl-th
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The categories of this paper are: alg-geom
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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: comp-gas