Logarithmic supertranslations as asymptotic symmetries of gravity at null infinity

Abstract

Logarithmic supertranslations have been shown recently to be symmetries of the gravitational field at spatial infinity. We extend this work by proving explicitly that they are also symmetries at null infinity. We also show that the logarithmic supertranslation charges match at the ``corner" where spatial infinity and null infinity meet. This fully establishes that the asymptotic symmetry group of gravity in the asymptotically flat context contains the logarithmic supertranslations.