Rj. Low, SINGULARITY THEOREMS AND THE [GENERAL-RELATIVITY PLUS ADDITIONAL MATTER FIELDS] FORMULATION OF METRIC THEORIES OF GRAVITATION - COMMENT, General relativity and gravitation, 27(9), 1995, pp. 969-972
Many metric theories of gravitation can be transformed into general re
lativity with matter fields. We consider the circumstances under which
such a transformation may be used to study the singularity structure
(where in this context, singularities are characterised by incomplete
causal geodesics).