Francesco Alessio "From BMS symmetries to the soft graviton theorem" (part I)

Monday 24 Jun 2019, 16:00 → 18:00 Europe/Rome

0M01 (Dipartimento di Fisica "E. Pancini")

In these short lectures, I will talk about the connection between the asymptotic symmetries of general relativity, in particular of BMS symmetries, and Weinberg’s soft graviton theorem. The BMS group was discovered by Sachs in the 1962 and the soft graviton theorem by Weinberg in the 1964, but for about fifty years these infrared properties of general relativity remained totally uncorrelated. Only recently, in a beautiful piece of research, it has been understood that the quantum Ward identities associated to the BMS invariance of the gravitational S-matrix are equivalent to the soft graviton theorem. In these introductory lectures, I will outline the link between these two subjects which represents one of the most active field of research in the theoretical physics of Gravity.