Soft gravitational radiation from multi-body collisions

• Published in: The journal of high energy physics Vol. 2021; no. 11; pp. 1 - 25
• Main Authors: Addazi, Andrea, Zeng, Kaiqiang Alan
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-11-2021; Springer Nature B.V; SpringerOpen
• Subjects: Black Holes; Classical and Quantum Gravitation; Classical Theories of Gravity; Elastic scattering; Elementary Particles; Energy spectra; Gravitational waves; Gravitons; High energy physics; Inelastic scattering; Models of Quantum Gravity; Particle collisions; Particle spin; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Radiation; Regular Article - Theoretical Physics; Relativity Theory; String Theory; Classical Theories of Gravity; Black Holes; Models of Quantum Gravity
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP11(2021)193

A
bstract
We derive a universal expression for the gravitational radiation energy spectrum
dE
GW
/
dω
at sub-leading order emitted from a generic gravitational hard scattering of multi-particles or multi-bodies. Our result includes all
O
(
ω
) corrections to the gravitational radiation flux from a generic 2
→ N
collision, in both the cases of massless and massive particles/bodies. We also show the dependence of the radiation energy flux by the quantum spin in case of particle collisions. Then, we consider the specific case of a gravitational elastic scattering of two massive bodies, i.e.
m
+
M → m
+
M
with
m, M
the masses of the two bodies respectively. We demonstrate that in this case all
O
(
ω
) contributions to the energy flux exactly cancel each others. Nevertheless, we also show that, for a 2
→
2 inelastic scattering, the inclusion of sub-leading soft gravitons leads to a not zero radiation flux, having a simple expression in certain asymptotic regimes. Our results can be applied to the case of Black Hole collisions with possible testable implications in gravitational waves physics.