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Searching for Kerr in the 2PM amplitude

Aoude, Rafael and Haddad, Kays and Helset, Andreas (2022) Searching for Kerr in the 2PM amplitude. Journal of High Energy Physics, 2022 (7). Art. No. 72. ISSN 1029-8479. doi:10.1007/jhep07(2022)072.

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The classical scattering of spinning objects is well described by the spinor-helicity formalism for heavy particles. Using these variables, we derive spurious-pole-free, all-spin opposite-helicity Compton amplitudes (factorizing on physical poles to the minimal, all-spin three-point amplitudes) in the classical limit for QED, QCD, and gravity. The cured amplitudes are subject to deformations by contact terms, the vast majority of whose contributions we can fix by imposing a relation between spin structures — motivated by lower spin multipoles of black hole scattering — at the second post-Minkowskian (2PM) order. For QED and gravity, this leaves a modest number of unfixed coefficients parametrizing contact-term deformations, while the QCD amplitude is uniquely determined. Our gravitational Compton amplitude allows us to push the state-of-the-art of spinning-2PM scattering to any order in the spin vectors of both objects; we present results here and in the supplementary material file 2PMSpin8Aux.nb up to eighth order in the spin vectors. Interestingly, despite leftover coefficients in the Compton amplitude, imposing the aforementioned relation between spin structures uniquely fixes some higher-spin parts of the 2PM amplitude.

Item Type:Article
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URLURL TypeDescription Paper Information
Aoude, Rafael0000-0001-9259-9257
Haddad, Kays0000-0002-1182-2750
Helset, Andreas0000-0002-5904-3748
Additional Information:© 2022 The Authors. This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited. Article funded by SCOAP3. Received 30 March 2022. Revised 25 May 2022. Accepted 14 June 2022. Published 12 July 2022. Calculations at one-loop order were performed using FeynCalc [89–91]. We would like to thank Lucile Cangemi, Henrik Johansson, Andrés Luna, Paolo Pichini, and Justin Vines for enlightening discussions. We also thank Francesco Alessio, Clifford Cheung, Paolo Di Vecchia, Alessandro Georgoudis, Alex Ochirov, Julio Parra-Martinez, and Ingrid VazquezHolm for conversations on related topics. We are grateful to Zvi Bern, Dimitrios Kosmopoulos, Andrés Luna, Radu Roiban, and Fei Teng for sharing a preliminary draft of their concurrent work [92] and for comments on this manuscript. We are similarly grateful to Yilber Fabian Bautista, Alfredo Guevara, Chris Kavanagh, and Justin Vines for sharing unpublished results, and additionally to Justin Vines for sharing unpublished notes. We thank Henrik Johansson for providing feedback on this manuscript. RA’s research is funded by the F.R.S-FNRS project no. 40005600. KH is grateful to Nordita for their hospitality. KH is supported by the Knut and Alice Wallenberg Foundation under grant KAW 2018.0116 (From Scattering Amplitudes to Gravitational Waves) and the Ragnar Söderberg Foundation (Swedish Foundations’ Starting Grant). AH is supported by the DOE under grant no. DE- SC0011632 and by the Walter Burke Institute for Theoretical Physics.
Group:Walter Burke Institute for Theoretical Physics
Funding AgencyGrant Number
Fonds de la Recherche Scientifique (FNRS)40005600
Knut and Alice Wallenberg FoundationKAW 2018.0116
Ragnar Söderberg FoundationUNSPECIFIED
Department of Energy (DOE)DE-SC0011632
Walter Burke Institute for Theoretical Physics, CaltechUNSPECIFIED
Subject Keywords:Black Holes, Effective Field Theories, Scattering Amplitudes, Classical Theories of Gravity
Issue or Number:7
Record Number:CaltechAUTHORS:20220714-369179000
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Official Citation:Aoude, R., Haddad, K. & Helset, A. Searching for Kerr in the 2PM amplitude. J. High Energ. Phys. 2022, 72 (2022).
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:115541
Deposited By: George Porter
Deposited On:14 Jul 2022 22:41
Last Modified:14 Jul 2022 22:41

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