Projective and Ricci collineations in general relativity
The thesis considers various problems in general relativity concerning projective and Ricci collineations. A result due to Yano in the maximum dimension of the projective algebra on a non-flat space-time is improved using a pointwise classification scheme. The converse of a result, relating Weyl projective vector fields and curvature collineations under certain well defined circumstances, is given. A result is presented showing that, under specified conditions a space-time admitting a proper special projective vector field admits a proper special conformal vector field and vice versa. The work done on Ricci/Matter collineations gives a general mathematical treatment of these vector fields where particular emphasis is placed on decomposable space-times. Problems of differentiability, extendibility, etc are described.