A burst of gravitational radiation causes the gravitational memory effect. We also have similar memory effects in other theories containing massless particles. It has been found that the memory effects are related to the soft theorems and the asymptotic symmetries in asymptotically flat spacetime. In this talk, I will focus on electromagnetism, and show that the electromagnetic memory effect is the conservation law of the asymptotic symmetry (i.e., large U(1) gauge symmetry). I also explain the relation to the soft photon theorem.

Host: Pranjal Nayak