Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Two-Loop Four-Graviton Scattering Amplitudes   We present the analytic form of the two-loop four-graviton scattering
amplitudes in Einstein gravity. To remove ultraviolet divergences we include
counterterms quadratic and cubic in the Riemann curvature tensor. The two-loop
numerical unitarity approach is used to deal with the challenging momentum
dependence of the interactions. We exploit the algebraic properties of the
integrand of the amplitude in order to map it to a minimal basis of Feynman
integrals. Analytic expressions are obtained from numerical evaluations of the
amplitude. Finally, we show that four-graviton scattering observables depend on
fewer couplings than naively expected.

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The categories of this paper are: quant-ph
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The categories of this paper are: adap-org
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The categories of this paper are: cond-mat
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The categories of this paper are: nucl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: q-bio
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The categories of this paper are: solv-int
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The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
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The categories of this paper are: math
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The categories of this paper are: nlin
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The categories of this paper are: mtrl-th
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The categories of this paper are: math-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: stat
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The categories of this paper are: q-fin