GRAMPA 2025 at Institut Henri Poincaré

Contribution List

1. Reception

01/07/2025, 09:30

2. Lecture

Laura Bernard

01/07/2025, 10:00

Analytic modelling of gravitational waves

3. Lecture

Laura Bernard

01/07/2025, 11:30

Analytic modelling of gravitational waves

4. Seminar: Soft theorems for scattering on plane wave backgrounds

Sonja Klisch

01/07/2025, 14:30

We have seen in the last few years that our understanding of scattering amplitudes in flat space can be leveraged for high-precision calculations in classical GR. In this talk I will motivate why you should also care about the structures of amplitudes on non-trivial backgrounds - not just flat space! One structure that is fundamental in our study of flat space amplitudes is soft factorisation....

5. Seminar: Time-dependent solutions of Biadjoint Scalar Field Theories

Kymani Armstrong-Williams

01/07/2025, 15:45

Biadjoint scalar field theories appear in the study of scattering amplitudes and classical solutions in gauge, gravity and related theories. In this talk, we present new exact solutions of biadjoint scalar field theory, showing that time-dependent solutions are possible and analytically tractable. We generalise the theory to include mass and / or quartic terms, and also a coupling to a...

6. Lecture

Laura Bernard

02/07/2025, 10:00

Analytic modelling of gravitational waves

7. Lecture

Laura Bernard

02/07/2025, 11:30

Analytic modelling of gravitational waves

8. Seminar: Analytical Modelling of gravitational wave sources: Scalar-tensor theory and more.

Tamanna Jain

02/07/2025, 14:30

Abstract: In this talk, I will review the analytical results for constructing gravitational waveforms in scalar-tensor theory. In particular, I will first discuss the results in the effective one body (EOB) formalism at the 3PN order for the conservative part of the dynamics. I will then review the angular momentum flux computation at 1.5PN order, which includes: instantaneous terms, tails and...

9. Seminar: Scattering Waveforms with QFT and WQFT

Lara Bohnenblust

02/07/2025, 15:45

What can scattering amplitudes teach us about the gravitational waves we hope to hear? This talk outlines why accurate waveform models are vital for upcoming gravitational wave detectors and how the post‑Minkowskian (PM) expansion supports that goal.
I present the computation of the waveform observable through order G³ S² within the PM framework, comparing two strategies: a traditional QFT...

10. Lecture

Carlo Heissenberg

03/07/2025, 10:00

Soft theorems and radiative observables from amplitudes

11. Lecture

Carlo Heissenberg

03/07/2025, 11:30

Soft theorems and radiative observables from amplitudes

12. Seminar: Supertranslations from Scattering Amplitudes

Asaad Elkhidir

03/07/2025, 14:30

On-shell methods have found a new application to local observables
such as asymptotic radiation fields and gravitational waveforms. While these
observables are invariant under small gauge transformations, they are known to
depend on a choice of asymptotic gauge; in gravity on asymptotically Minkowski
spacetimes, this is a choice of BMS frame. In this talk, I will describe a
method for...

13. Seminar: Analytic Gravitational Waveforms: A Combined Fourier–Loop Amplitude Framework

Giacomo Brunello

03/07/2025, 15:45

Accurate modelling of gravitational-wave signals is essential for extracting masses, spins, and strong-field dynamics from detector data. Within the observable-based formalism, scattering waveforms are expressed as the Fourier transform of a five-point scattering amplitude in impact-parameter space. In this talk, I will introduce a novel approach to compute analytic waveforms, where we combine...

18. Poster session

03/07/2025, 16:30

14. Lecture

Carlo Heissenberg

04/07/2025, 10:00

Soft theorems and radiative observables from amplitudes

15. Lecture

Carlo Heissenberg

04/07/2025, 11:30

Soft theorems and radiative observables from amplitudes

16. Seminar: On-shell approaches for spinning binaries beyond GR

Panagiotis Marinellis

04/07/2025, 14:30

The detection of gravitational waves by the LIGO-VIRGO collaboration has marked a transformative era in astronomy, providing groundbreaking insights into the cosmos and creating new pathways for exploration. At the same time, advancements in the classical limit of quantum scattering amplitudes, particularly through the KMOC formalism, have enriched our understanding of compact binary...

17. Seminar: Perturbative Computations from Curved Spacetimes

Nabha Shah

04/07/2025, 15:45

Given the impressive results for classical observables obtained by field theoretic approaches to gravitational systems, we can ask if these tools can help us in other regimes and problems of interest. Amplitude tools are particularly well suited to derive observables for the binary system in a post-Minkowskian expansion, where they have achieved complete results to fourth order in Newton's...