Degeneracy of the b-boundary in general relativity

The b-boundary construction by B. Schmidt is a general way of providing a b oundary to a manifold with connection [12]. It has been shown to have undes irable topological properties however. C. J. S. Clarke gave a result showin g that for spacetimes, non-Hausdorffness is to be expected in general [3], but the argument contains some errors. We show that under somewhat differen t conditions on the curvature, the b-boundary will be non-Hausdorff, and il lustrate the degeneracy by applying the conditions to some well known exact solutions of general relativity.