Superrotations at Spacelike Infinity

Explore a groundbreaking talk on gravity in asymptotically flat spacetime at spacelike infinity. Delve into a consistent set of boundary conditions that enhance the Bondi-Metzner-Sachs group with smooth superrotations and new subleading symmetries. Discover how fluctuations of the boundary structure lead to divergences in the symplectic form, necessitating a renormalization procedure for finite canonical generators. Learn about the incorporation of boundary terms into the symplectic structure, derived from a linearized spin-two boundary field on a curved background with positive cosmological constant. Examine the formation of a non-linear algebra by canonical generators under the Poisson bracket and verify the consistency of this structure with the Jacobi identity. This one-hour presentation, part of the Thematic Programme on "Carrollian Physics and Holography" at the Erwin Schrödinger International Institute for Mathematics and Physics, offers profound insights into advanced concepts in theoretical physics and mathematics.