Speaker
Anna Sakovich, Uppsala University
Abstract
We will introduce the class of causally-null-compactifiable spacetimes which includes future developments of compact initial data sets and regions exhausting asymptotically flat space-times. These spacetimes can be canonically converted into compact timed metric spaces using the cosmological time function of Andersson-Galloway-Howard and the null distance of Sormani-Vega. We will discuss various intrinsic notions of distance between causally-null-compactifiable spacetimes and show that some of them are definite in the sense that they are equal to zero if and only if there is a time-oriented Lorentzian isometry between the spacetimes. These definite distances give rise to notions of convergence of spacetimes to limits that are not necessarily smooth. This is joint work with Christina Sormani.