Some perfect fluid solutions of Einstein's field equations without symmetries

Metrics of the form ds2 = N2(x1,xsup(n))(dx1)2+gsub(ab) (xsup(n))dxsup(a)dxsup(b) are considered which are subject to the conditions that the time-like 3-space (with metric gsub(ab)) is conformally flat, that its Ricci tensor has at most two different eigenvalues, and that the 4-velocity is an eigenvector of this Ricci tensor. The perfect fluid (or dust) solutions are necessarily of Petrov type D or O, and in the general case they do not admit a Killing vector. All rotating solutions are given explicitly. The non-rotating solutions are either conformally flat (and thus known) or (if of type D) contained in a class of solutions investigated by previous workers. (author)