Radiation-reaction in the Effective Field Theory approach to Post-Minkowskian dynamics

Abstract

We extend the Post-Minkowskian (PM) effective field theory (EFT) approach to incorporate conservative and dissipative radiation-reaction effects in a unified framework. This is achieved by implementing the Schwinger-Keldysh “in-in” formalism and separating conservative and non-conservative terms according to the formulation in [1], which we show promotes Feynman’s i0-prescription and cutting rules to a prominent role at the classical level. The resulting integrals, involving both Feynman and retarded propagators, can be bootstrapped to all orders in the velocity via differential equations with boundary conditions including potential and radiation modes. As a paradigmatic example we provide an ab initio derivation of the classical solution to the scattering problem in general relativity to $$ \mathcal{O} $$ O (G3). For the sake of completeness, we also reproduce the leading order radiation-reaction effects in classical electrodynamics.

Poincaré invariance of spinning binary dynamics in the post-Minkowskian Hamiltonian approach

“…It would be interesting to see if we can overcome the difficulties at higher orders, such as radiation reaction effects (see e.g. [35][36][37][38][39][40][41][42][43][44][45] for the effects at the 3PM and 4PM orders) and succeed in constructing the boost generators. The construction of the 2PM boost generators is underway.…”

Orbital precession and hidden symmetries in scalar-tensor theories

“…(ii) to use the t-channel dispersion relation to derive sum rules for the precession and period in terms of new UV physics/states (along the lines of [118,119] and in the spirit of other recent amplitude constraints on the disformal coupling and scalar-tensor theories [55,[155][156][157][158]), (iii) to include spin for the compact objects, along the lines of the PN analysis in [57] which identified the leading disformal coupling to the binary's spin and orbital angular momentum, (iv) to go to higher PM orders: one of the main takeaways from the above should be that adding a scalar is relatively straightforward in this amplitude framework, and since 3PM and 4PM GR amplitudes are already known it should be possible to include a scalar to that order as well, (v) to include the dissipative effects from radiation, including the emitted power and gravitational wave phase evolution, to make contact with waveform templates. For instance, this could be done in the PM framework by adapting the EFT approach of [159] to include non-minimal coupling to a scalar field. This is beyond the scope of the current investigation and is left for the future.…”

Absorptive effects and classical black hole scattering

“…Recent years have seen tremendous advances in these weak-field perturbative approaches. In particular, new and powerful calculational methods based on relativistic scattering amplitudes [24][25][26][27][28][29][30][31][32][33][34][35][36] and worldline effective field theories (EFT) [37][38][39][40][41][42][43][44][45][46], have allowed for rapid progress in understanding the PM scattering regime of the gravitational two-body problem. These approaches share the common strategy of initially framing the problem in quantum mechanical language, and then using the eventual classical or ℏ → 0 limit as an additional JHEP03(2024)015 expansion leading to vast simplifications in the required calculations.…”