Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Direct Integration for Multi-leg Amplitudes: Tips, Tricks, and When They
  Fail   Direct hyperlogarithmic integration offers a strong alternative to
differential equation methods for Feynman integration, particularly for
multi-particle diagrams. We review a variety of results by the authors in which
this method, employed with some care, can compute diagrams of up to eight
particles and four loops. We also highlight situations in which this method
fails due to an algebraic obstruction. In a large number of cases the
obstruction can be associated with a Calabi-Yau manifold.

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The categories of this paper are: physics
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The categories of this paper are: patt-sol
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The categories of this paper are: math-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: cond-mat
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The categories of this paper are: stat
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The categories of this paper are: acc-phys
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The categories of this paper are: funct-an
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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: comp-gas
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The categories of this paper are: solv-int
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The categories of this paper are: econ
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The categories of this paper are: ao-sci
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex