| Speaker: | Andrea |
|---|---|
| Title: | A New Perspective on Gravity: Black Hole Interactions from On- Shell Amplitudes |
| Date (JST): | Wed, Oct 08, 2025, 13:30 - 15:00 |
| Place: | Seminar Room A |
| Abstract: |
Recently, the amplitude community has shown that the interactions of black holes can be described purely in terms of minimal building blocks known as on-shell amplitudes and their classical limit, without ever needing a Lagrangian, gauge choices, or equations of motion. In just a few years, this perspective has led to state-of-the-art results in general relativity, uncovered new theoretical structures, and attracted a rapidly growing research community. However, little is still known about whether this approach can tackle non perturbative aspects of black holes. Two particularly challenging tests are the merger of binary black holes and the Hawking radiation they emit. In this talk, I will argue that both can be approached with an on-shell mindset by considering a universal mass-changing three-point amplitude, matched to physical and gauge-invariant quantities. Once the matching conditions are specified, this simple building block can be iterated, as in any other perturbative on-shell scheme in QFT, to compute higher-loop corrections or processes with more external states. As an application, I will show how to derive conservation laws and memory waveforms in black hole mergers. I will also explain how to compute classical and quantum mass-changing effects arising from event horizons. In the quantum case, Hawking radiation can be recovered from an on-shell cut treated as a decay process, allowing us to reproduce Hawking radiation for an isolated black hole and discuss its impact on binary scattering. |
