Loop-the-Loop-2: Feynman calculus and its applications to gravity and particle physics

Session

Scattering Amplitudes in Gravity

11 Nov 2025, 10:30

18. Post-Minkowskian Integrals at 4 Loops: 0SF, 1SF, and 2SF

Mathias Driesse

11/11/2025, 10:30

The application of quantum field theory methods to the relativistic two-body problem in gravity has led to extraordinary advances in recent years, with applications to real gravitational wave physics. I will demonstrate how the WQFT formalism leads to particularly interesting Feynman integrals that at 4 loops fit neatly into a hierarchy of increasing difficulty: 0SF, 1SF, and 2SF. I will...

19. Binary Kerr black-hole scattering at 2PM from quantum higher-spin Compton

Lucile Cangemi

11/11/2025, 11:00

In this talk, I’ll discuss how the dynamics of spinning sources are incorporated when computing post-Minkowskian (PM) observables within the quantum field theory framework. Our goal is to capture the dynamics of a Kerr black hole rather than a generic compact object. I will present our candidate tree-level amplitude for gravitational Compton scattering, fixed using tools from massive...

20. Non linear memory from reverse unitarity

Alessandro Georgoudis

11/11/2025, 11:40

I will present a recent computation of the nonlinear gravitational-wave memory in two-body scattering, using scattering amplitudes and soft theorems in the weak-field post-Minkowskian regime. The effect first appears at NNLO PM, and I will show how its evaluation reduces to simpler, lower-point cut two-loop integrals.

21. High Precision Kerr Black Hole Scattering

Dogan Akpinar

11/11/2025, 12:10

Scattering amplitudes have emerged as a powerful tool for predicting physical observables in two-body gravitational interactions. In this talk, I will present state-of-the-art results for the scattering of a spinning and non-spinning black hole, modelled as point particles in fixed-spin representations. A key complication in this approach is the mixing of classical and quantum contributions,...

14. The multipolar post-Minkowskian iteration and tails of memory

David Trestini

11/11/2025, 14:30

In traditional post-Newtonian methods, the spacetime is split into a near zone and an exterior vacuum zone. In the near zone, the metric is solved by iterating the Einstein equations in a small post-Newtonian (PN) parameter, either the relative velocity of the binary or the relative inverse separation; the power counting is done in powers of c. In the exterior vacuum zone, no assumptions are...

15. Post-Newtonian tidal effects in the gravitational waveform from binary inspirals in scalar-tensor theories

Eve Dones

11/11/2025, 15:00

With the advent of third-generation gravitational-wave detectors, accurately modelling signals from binary neutron stars is essential to disentangle matter effects from possible deviations from general relativity. In this talk, I will present recent results on tidal effects in scalar–tensor theories, which are expected to be more prominent than in general relativity due to the presence of a...

16. High precision scattering waveforms from the Self Force approach

Davide Usseglio

11/11/2025, 15:40

In this talk I will review how to get analytical information on scattering waveforms by employing the Self Force approach, which contains resumed contributions from both the weak field approximation, or post-Minkowskian (PM), and the low velocity limit, i.e. post-Newtonian (PN) approximation. By leveraging this feature it would be possible to get analytical information at very high order in...

17. Scalar Black Hole Love numbers to O(G^7)

Giulia Isabella

11/11/2025, 16:10

At wavelengths large compared to the source size, any compact object admits a point-particle EFT whose finite-size effects are encoded by Love numbers. In this talk I will discuss a novel method to compute gravitational wave amplitudes by reinterpreting the Feynman diagram expansion as a Born series, solution of an effective wave equation. This method enables efficient, systematic calculations...