Seminarium Teorii Względności i Grawitacji

Following the recent work of Henneaux and Troessaert, which revisits the problem of spacetime symmetries at spatial infinity, we analyze this problem using a Bondi-type metric without determinant condition as our starting point. We find that allowing only such spacetimes that radiate only a finite amount of energy provides additional damping factors such that no parity conditions have to be imposed in order to cancel divergences in the asymptotic symplectic structure. It turns out that in this case the symmetries at spatial infinity form the BMS symmetry appended with an additional infinite set of abelian symmetries. We furthermore find that imposing the determinant condition would result in a drastic reduction of symmetries, with no spatial (super) translations present. The talk will be also broadcasted in the room 1.40.