No abstract

We give an example of a causally well-behaved, singular space–time for which all singular-boundary constructions which fall in a certain wide class—a class which includes both the g-boundary and b-boundary—yield pathological topological properties. Specifically, for such a construction as applied to this example, a singular boundary point fails to be T1-related to an event of the original space–time. This example suggests that there may not exist any useful, generally applicable notion of the singular boundary of a space–time.

A simple result, restricting the behavior of a timelike curve under limitations on its integrated acceleration, is obtained and discussed.