Penrose's conformal approach to the study of asymptotics leads to a singular conformal structure at spatial infinity, particularly in spacetimes with non-vanishing ADM mass. Two widely used formulations to resolve this singularity were developed by A. Ashtekar et al. and H. Friedrich. In this talk, I will discuss the details of these two approaches and their relation, on Minkowski spacetime and in a more general setting.

Talk recording : Yes, I don't mind it.