On space-times admitting shear-free, irrotational, geodesic null congruences

Abstract

Space-times admitting a shear-free, irrotational, geodesic null congruence are studied. Attention is focused on those space-times in which the gravitational field is a combination of a perfect fluid and null radiation.

Latex, 4 pages. Published in "Analytical and Numerical Approaches to Relativity: Sources of Gravitational Radiation". Edts. C. Bona, J. Carot, L. Mas and J. Stela; U.I.B. Mallorca, pp. 266-270 (1998)