MSc. Deepali Singh and MSc. Maximilian Gaschler

T a l k : 6. November 2025

High-Precision Gravitational-Wave Physics from Linearized Gravity to Worldline Quantum Field Theory

One of the most important challenges in general relativity, is the gravitational two-body problem, where we attempt to understand and predict the dynamics and kinematics of two massive objects like black holes or neutron stars. Especially with high end detectors on the rise, it is essential to make precise theoretical predictions to interpret the observational data.

In this talk, we will start with the gravitational two-body problem and discuss it in Newton’s as well as Einstein’s framework. Then we will discuss linearized gravity where Einstein’s field equations reduce to a massless spin-2 field theory making it natural to apply quantum field theory methods.

We will then discuss Worldline Quantum Field Theory Framework, which is inspired by string theory, where we will attempt to streamline the problem by quantization. We will see how this framework has enabled physicists (Plefka et al) to obtain the most precise perturbative result to date, for the scattering of spinning black holes at the fifth order in G. Then we will see how the 4th loop computations reveal new mathematical structures: periods of Calabi-Yau manifolds which are previously known only from string compactifications. But now they appear in physical observables of classical gravity.

In this talk, we will trace the journey from linearized gravity to modern amplitude techniques and the emergence of rich algebraic geometry exploring the convergence of gravitational-wave physics, QFT, and differential geometry into a single framework of understanding the dynamics of spacetime.