Comment on ‘‘Failure of standard conservation laws at a classical change of signature’’

Hellaby and Dray hve recently claimed that matter conservation fails under a change of signature, compounding earlier claims that the standard junction conditions for signature change are unnecessary In fact, if the field equations are satisfied, then the junction conditions and the conservation equations are satisfied. The failure is rather that the authors did not make sense of the field equations and conservation equations, which are singular at a change of signature. © 1995 The American Physical Society.