Title：[NTU-NCTS String Seminar] Double graviton dressing and 2PM gravitational wave observables
Speaker：Dr. Karan Fernandes (NTNU)
Time: Nov. 10, 2023 (Fri.) 14:30-15:30
Venue: Rm. 815, Dept. of Physics, NTU

Abstract：
A recent proposal describes inelastic eikonal scattering processes in terms of gravitationally dressed elastic eikonal amplitudes, which can be used to derive gravitational wave observables (cf. arXiv: 2306.16488 [hep-th] for a review). In this talk, I discuss the generalization of the known single graviton dressing to include collinear double graviton corrections for eikonal amplitudes. The dressing is derived from a known Wilson line operator in the worldline formalism for gravitationally interacting theories, wherein next-to-eikonal corrections manifest as double graviton contributions. We show that the dressing can be factored into a coherent piece with contributions to all orders in the gravitational coupling constant, and a term quadratic in graviton modes. We use the double graviton dressing to derive 2PM or $G^2$ results for the waveform, emitted momentum spectrum and angular momentum. I conclude with a discussion on future directions and generalizations to higher PM orders.