Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Yetter-Drinfeld modules over weak Hopf algebras and the center
  construction   We introduce Yetter-Drinfeld modules over a weak Hopf algebra $H$, and show
that the category of Yetter-Drinfeld modules is isomorphic to the center of the
category of $H$-modules. The categories of left-left, left-right, right-left
and right-right Yetter-Drinfeld modules are isomorphic as braided monoidal
categories. Yetter-Drinfeld modules can be viewed as weak Doi-Hopf modules,
and, a fortiori, as weak entwined modules. If $H$ is finitely generated and
projective, then we introduce the Drinfeld double using duality results between
entwining structures and smash product structures, and show that the category
of Yetter-Drinfeld modules is isomorphic to the category of modules over the
Drinfeld double.

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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: acc-phys
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The categories of this paper are: econ
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The categories of this paper are: astro-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: stat
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The categories of this paper are: math-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: nlin
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The categories of this paper are: alg-geom
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The categories of this paper are: physics