Spinning gravitational waveforms from scattering amplitudes

by Prof. Gabriele Travaglini (Queen Mary)

Wednesday 30 Apr 2025, 14:00 → 15:15 Europe/Berlin

Auditorium (Notkestrasse 9)

While scattering amplitudes find their primary application to collider physics, describing the dynamics of the tiniest particles in the universe, they also characterise the interactions among some of the universe's most massive objects, such as black holes.  Violent black hole collisions occur where tremendous amounts of energy are emitted in the form of gravitational waves, and with the increasing precision of current and future experiments, it is now crucial to develop novel efficient methods for highly needed high-precision predictions. Thanks to their inherent simplicity, scattering amplitudes are ideally suited to this task, but one faces the challenge of extracting classical contributions efficiently. 

I will describe how working in a Heavy-mass Effective Field Theory (HEFT) allows to achieve this goal, dropping quantum-suppressed terms and hyper-classical corrections from the outset. I will then briefly discuss a few important applications of the HEFT amplitudes: the calculation of the two-loop (or third post-Minkowskian) scattering angle of two spinless black holes; the determination of the subleading (one-loop) scattering waveform for spinless black holes;  and finally, for the case of two spinning black holes, I will discuss the computation of leading-order waveforms in both general relativity and in theories with cubic deformations in the Riemann tensor.