Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hopf reductions, fluxes and branes   We use a series of reductions, T-dualities and liftings to construct
connections between fractional brane solutions in IIA, IIB and M-theory. We
find a number of phantom branes that are not supported by the geometry, however
materialize upon untwisting and/or Hopf-reduction.

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The categories of this paper are: comp-gas
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The categories of this paper are: chem-ph
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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: dg-ga
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: physics
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The categories of this paper are: q-bio
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The categories of this paper are: bayes-an
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The categories of this paper are: stat
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The categories of this paper are: supr-con
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The categories of this paper are: adap-org
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The categories of this paper are: econ