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Gravitational Effective Field Theory Islands, Low-Spin Dominance, and the Four-Graviton Amplitude

We analyze constraints from perturbative unitarity and crossing on the leading contributions of higher-dimension operators to the four-graviton amplitude in four spacetime dimensions, including constraints that follow from distinct helicity configurations. We focus on the leading-order effect due to...

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Autores principales: Bern, Zvi, Kosmopoulos, Dimitrios, Zhiboedov, Alexander
Lenguaje:eng
Publicado: 2021
Materias:
Acceso en línea:https://dx.doi.org/10.1088/1751-8121/ac0e51
http://cds.cern.ch/record/2759011
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author Bern, Zvi
Kosmopoulos, Dimitrios
Zhiboedov, Alexander
author_facet Bern, Zvi
Kosmopoulos, Dimitrios
Zhiboedov, Alexander
author_sort Bern, Zvi
collection CERN
description We analyze constraints from perturbative unitarity and crossing on the leading contributions of higher-dimension operators to the four-graviton amplitude in four spacetime dimensions, including constraints that follow from distinct helicity configurations. We focus on the leading-order effect due to exchange by massive degrees of freedom which makes the amplitudes of interest infrared finite. In particular, we place a bound on the coefficient of the R 3 operator that corrects the graviton three-point amplitude in terms of the R 4 coefficient. To test the constraints we obtain nontrivial effective field-theory data by computing and taking the large-mass expansion of the one-loop minimally-coupled four-graviton amplitude with massive particles up to spin 2 circulating in the loop. Remarkably, we observe that the leading EFT coefficients obtained from both string and one-loop field-theory amplitudes lie in small islands. The shape and location of the islands can be derived from the dispersive representation for the Wilson coefficients using crossing and assuming that the lowest-spin spectral densities are the largest. Our analysis suggests that the Wilson coefficients of weakly-coupled gravitational physical theories are much more constrained than indicated by bounds arising from dispersive considerations of 2 → 2 scattering. The one-loop four-graviton amplitudes used to obtain the EFT data are computed using modern amplitude methods, including generalized unitarity, supersymmetric decompositions and the double copy.
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institution Organización Europea para la Investigación Nuclear
language eng
publishDate 2021
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spelling cern-27590112023-10-04T06:49:29Zdoi:10.1088/1751-8121/ac0e51http://cds.cern.ch/record/2759011engBern, ZviKosmopoulos, DimitriosZhiboedov, AlexanderGravitational Effective Field Theory Islands, Low-Spin Dominance, and the Four-Graviton Amplitudehep-phParticle Physics - Phenomenologyhep-thParticle Physics - TheoryWe analyze constraints from perturbative unitarity and crossing on the leading contributions of higher-dimension operators to the four-graviton amplitude in four spacetime dimensions, including constraints that follow from distinct helicity configurations. We focus on the leading-order effect due to exchange by massive degrees of freedom which makes the amplitudes of interest infrared finite. In particular, we place a bound on the coefficient of the R 3 operator that corrects the graviton three-point amplitude in terms of the R 4 coefficient. To test the constraints we obtain nontrivial effective field-theory data by computing and taking the large-mass expansion of the one-loop minimally-coupled four-graviton amplitude with massive particles up to spin 2 circulating in the loop. Remarkably, we observe that the leading EFT coefficients obtained from both string and one-loop field-theory amplitudes lie in small islands. The shape and location of the islands can be derived from the dispersive representation for the Wilson coefficients using crossing and assuming that the lowest-spin spectral densities are the largest. Our analysis suggests that the Wilson coefficients of weakly-coupled gravitational physical theories are much more constrained than indicated by bounds arising from dispersive considerations of 2 → 2 scattering. The one-loop four-graviton amplitudes used to obtain the EFT data are computed using modern amplitude methods, including generalized unitarity, supersymmetric decompositions and the double copy.We analyze constraints from perturbative unitarity and crossing on the leading contributions of higher-dimension operators to the four-graviton amplitude in four spacetime dimensions, including constraints that follow from distinct helicity configurations. We focus on the leading-order effect due to exchange by massive degrees of freedom which makes the amplitudes of interest infrared finite. In particular, we place a bound on the coefficient of the $R^3$ operator that corrects the graviton three-point amplitude in terms of the $R^4$ coefficient. To test the constraints we obtain nontrivial effective field-theory data by computing and taking the large-mass expansion of the one-loop minimally-coupled four-graviton amplitude with massive particles up to spin 2 circulating in the loop. Remarkably, we observe that the leading EFT coefficients obtained from both string and one-loop field-theory amplitudes lie in small islands. The shape and location of the islands can be derived from the dispersive representation for the Wilson coefficients using crossing and assuming that the lowest-spin spectral densities are the largest. Our analysis suggests that the Wilson coefficients of weakly-coupled gravitational physical theories are much more constrained than indicated by bounds arising from dispersive considerations of $2 \to 2$ scattering. The one-loop four-graviton amplitudes used to obtain the EFT data are computed using modern amplitude methods, including generalized unitarity, supersymmetric decompositions and the double copy.arXiv:2103.12728CERN-TH-2021-035oai:cds.cern.ch:27590112021-03-23
spellingShingle hep-ph
Particle Physics - Phenomenology
hep-th
Particle Physics - Theory
Bern, Zvi
Kosmopoulos, Dimitrios
Zhiboedov, Alexander
Gravitational Effective Field Theory Islands, Low-Spin Dominance, and the Four-Graviton Amplitude
title Gravitational Effective Field Theory Islands, Low-Spin Dominance, and the Four-Graviton Amplitude
title_full Gravitational Effective Field Theory Islands, Low-Spin Dominance, and the Four-Graviton Amplitude
title_fullStr Gravitational Effective Field Theory Islands, Low-Spin Dominance, and the Four-Graviton Amplitude
title_full_unstemmed Gravitational Effective Field Theory Islands, Low-Spin Dominance, and the Four-Graviton Amplitude
title_short Gravitational Effective Field Theory Islands, Low-Spin Dominance, and the Four-Graviton Amplitude
title_sort gravitational effective field theory islands, low-spin dominance, and the four-graviton amplitude
topic hep-ph
Particle Physics - Phenomenology
hep-th
Particle Physics - Theory
url https://dx.doi.org/10.1088/1751-8121/ac0e51
http://cds.cern.ch/record/2759011
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AT kosmopoulosdimitrios gravitationaleffectivefieldtheoryislandslowspindominanceandthefourgravitonamplitude
AT zhiboedovalexander gravitationaleffectivefieldtheoryislandslowspindominanceandthefourgravitonamplitude