A CONFORMAL VECTOR IN SHEARING SPACE-TIMES

We analyse a class of spherically symmetric solutions to the Einstein field equations which are accelerating, expanding and shearing. These solutions are characterised thermodynamically by an equation of state, p = mu + const, which is a generalisation of the stiff equation of st ate. In this paper we characterise this class of shearing solutions ge ometrically by showing that it admits a conformal symmetry. This sugge sts the possibility of finding other solutions in spherically symmetri c models by imposing the requirement of a conformal symmetry on space- time.