Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Involutory Hopf group-coalgebras and flat bundles over 3-manifolds   Given a group G, we use involutary Hopf G-coalgebras to define a scalar
invariant of flat G-bundles over 3-manifolds. When G=1, this invariant equals
to the one of 3-manifolds constructed by Kuperberg from involutary Hopf
algebras. We give examples which show that this invariant is not trivial.

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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: nlin
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
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The categories of this paper are: funct-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: cond-mat
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The categories of this paper are: gr-qc
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The categories of this paper are: supr-con
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The categories of this paper are: ao-sci
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The categories of this paper are: chao-dyn
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The categories of this paper are: plasm-ph