Scattering amplitudes play a vital role in understanding the interactions between fundamental particles. They underpin calculations of various physical phenomena, including scattering probabilities, gravitational waveforms, cosmological correlators, and can be used to constraint on extensions to the Standard Model.
Traditionally, computing these quantities using perturbation theory is challenging.

Our research group has made significant progress in developing efficient methods for evaluating scattering amplitudes and physical observables. This has been achieved through novel approaches to constructing and analytically evaluating scattering amplitudes, enabling us to connect them to observable phenomena.
Calculations with massless particles can be complicated by the presence of infrared divergences, hindering the extraction of exact results. We address this by introducing approaches that define specific, infrared-finite observables and integrals, leading to exact formulae. The duality between colour factors and kinematic factors allows us to construct many gravitational amplitudes from gauge theory amplitudes. This has enabled the calculation of the ultraviolet behaviour of maximal supergravity at five-loop order,2 confirming earlier (2010) predictions based on symmetry analysis.
Significant insights into classical gravitational radiation have been gained by deriving the classical gravitational waveforms emitted during two-body interactions using quantum scattering amplitudes. The KMOC4 and newly introduced exponential formalisms5 are crucial tools for this derivation, developed by our research group. Finally, advanced mathematical techniques, including differential equations, and integration-by-part identities, have been developed by our group to facilitate the efficient evaluation of Feynman integrals in the
context of scattering amplitudes.

Researchers involved
- Brando BELLAZZINI
- Carlo HEISSENBERG
- David KOSOWER
- Gregory KORCHEMSKY
- Pierre VANHOVE