Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unimodular Trees versus Einstein Trees   The maximally helicity violating (MHV) tree level scattering amplitudes
involving three, four or five gravitons are worked out in Unimodular Gravity.
They are found to coincide with the corresponding amplitudes in General
Relativity. This a remarkable result, insofar as both the propagators and the
vertices are quite different in both theories.

27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
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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: adap-org
16
The categories of this paper are: stat
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The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex