Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hopf automorphisms and twisted extensions   We give some applications of a Hopf algebra constructed from a group acting
on another Hopf algebra A as Hopf automorphisms, namely Molnar's smash
coproduct Hopf algebra. We find connections between the exponent and
Frobenius-Schur indicators of a smash coproduct and the twisted exponents and
twisted Frobenius-Schur indicators of the original Hopf algebra A. We study the
category of modules of the smash coproduct.

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The categories of this paper are: ao-sci
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The categories of this paper are: q-fin
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The categories of this paper are: econ
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-th
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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: astro-ph
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The categories of this paper are: cs
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The categories of this paper are: mtrl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: cond-mat
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The categories of this paper are: plasm-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: alg-geom