Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lorentz-Covariant Green-Schwarz Superstring Amplitudes   In a recent paper, the BRST formalism for the gauge-fixed N=2 twistor-string
was used to calculate Green-Schwarz supersring scattering amplitudes with an
arbitrary number of loops and external massless states. Although the
gauge-fixing procedure preserved the worldsheet N=2 superconformal invariance
of the twistor-string, it broke the target-space SO(9,1) super-Poincar\'e
invariance down to an SU(4)xU(1) subgroup. In this paper, generators for the
SO(9,1) super-Poincar\'e transformations, as well as manifestly covariant
vertex operators, are explicitly constructed out of the gauge-fixed matter
fields. The earlier calculated amplitudes are then expressed in manifestly
Lorentz-covariant notation.

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The categories of this paper are: math
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The categories of this paper are: hep-ph
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The categories of this paper are: q-bio
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The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
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The categories of this paper are: q-alg
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The categories of this paper are: acc-phys
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-lat
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The categories of this paper are: chem-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: solv-int
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The categories of this paper are: plasm-ph
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The categories of this paper are: bayes-an