Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 1/4 BPS States and Non-Perturbative Couplings in N=4 String Theories   We compute certain 2K+4-point, one-loop couplings in the type IIA string
compactified on K3 x T^2, which are related to a topological index on this
manifold. Their special feature is that they are sensitive to only short and
intermediate BPS multiplets. The couplings derive from underlying prepotentials
G[K](T,U), which can be nicely summed up into a fundamental generating
function. In the dual heterotic string on T^6, the amplitudes describe
non-perturbative gravitational corrections to K-loop amplitudes due to bound
states of fivebrane instantons with heterotic world-sheet instantons. We argue,
as a consequence, that our results also give information about instanton
configurations in six dimensional Sp(2k) gauge theories on T^6.

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The categories of this paper are: chao-dyn
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The categories of this paper are: q-bio
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The categories of this paper are: econ
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The categories of this paper are: eess
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The categories of this paper are: quant-ph
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The categories of this paper are: cs
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: math-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: ao-sci