Journal of High Energy Physics (May 2024)

Binary black holes and quantum off-shell recursion

  • Kyoungho Cho,
  • Kwangeon Kim,
  • Kanghoon Lee

DOI
https://doi.org/10.1007/JHEP05(2024)050
Journal volume & issue
Vol. 2024, no. 5
pp. 1 – 84

Abstract

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Abstract The quantum off-shell recursion provides an efficient and universal computational tool for loop-level scattering amplitudes. In this work, we present a new comprehensive computational framework based on the quantum off-shell recursion for binary black hole systems. Using the quantum perturbiner method, we derive the recursions and solve them explicitly up to two-loop order. We introduce an indicator that enables straightforward distinguishing diagrams and deriving integral families in the context of off-shell recursions. By employing the soft expansion technique, we remove irrelevant terms from the loop integrands and express them in terms of master integrals. We classify the one-loop and the two-loop classical diagrams, and their loop integrands are represented by linear combinations of the master integrals. Finally, we explicitly calculate the classical scalar 2 → 2 amplitudes in the potential region up to the 3PM order and reproduce the known results.

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