It is shown that conformal symmetric space-times admitting an infinitesimal conformal symmetry are either of type O or N. Those of type N represent plane gravitational waves with parallel rays, provided the Einstein tensor is invariant of the infinitesimal conformal symmetry.
No takes yet. Share an insight, caveat, or question.
Ramesh Sharma (1988) studied this question.
Synapse has enriched 4 closely related papers on similar clinical questions. Consider them for comparative context: