Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Torons and D-Brane Bound States   We interpret instantons on a torus with twisted boundary conditions, in terms
of bound states of branes. The interplay between the SU(N) and U(1) parts of
the U(N) theory of N 4-branes allows the construction of a variety of bound
states. The SU(N) and U(1) parts can contribute fractional amounts to the total
instanton number which is integral. The geometry of non-self intersecting
two-cycles in $T^4$ sheds some light on a number of properties of these
solutions.

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The categories of this paper are: astro-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: mtrl-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: econ
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-th
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The categories of this paper are: cs
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The categories of this paper are: atom-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-lat
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The categories of this paper are: q-alg
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The categories of this paper are: hep-ph
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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: quant-ph