Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Brauer group is not a derived invariant   In this short note we observe that the recent examples of derived-equivalent
Calabi-Yau 3-folds with different fundamental groups also have different Brauer
groups, using a little topological K-theory.

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The categories of this paper are: physics
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The categories of this paper are: hep-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: eess
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The categories of this paper are: stat
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The categories of this paper are: chao-dyn
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The categories of this paper are: funct-an
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The categories of this paper are: supr-con
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The categories of this paper are: acc-phys
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The categories of this paper are: math-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-ph
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The categories of this paper are: nlin
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The categories of this paper are: gr-qc
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The categories of this paper are: comp-gas