Asymptotic Symmetries and Charges in De Sitter Space

Understand

The asymptotic symmetry group (ASG) at future null infinity (I^+) of four-dimensional de Sitter spacetimes is defined and shown to be given by the group of three-dimensional diffeomorphisms acting on I^+.

• Finite charges are constructed for each choice of ASG generator together with a two-surface on I^+.
• A conservation equation is derived relating the evolution of the charges with the radiation flux through I^+.