Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the BRST Operator Structure of the N=2 String   The BRST operator cohomology of $N=2$ $2d$ supergravity coupled to matter is
presented. Descent equations for primary superfields of the matter sector are
derived. We find one copy of the cohomology at ghost number one, two
independent copies at ghost number two, and conjecture that there is a copy at
ghost number three. The $N=2$ string has a twisted $N=4$ superconformal
symmetry generated by the $N=2$ superstress tensor, the BRST supercurrent, the
antighost superfield, and the ghost number supercurrent.

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The categories of this paper are: supr-con
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The categories of this paper are: astro-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: stat
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The categories of this paper are: plasm-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: econ
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The categories of this paper are: chao-dyn
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The categories of this paper are: adap-org
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The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: nlin
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The categories of this paper are: comp-gas