Homothetic motions of spherically symmetric space-times

The homotheties of spherically symmetric space-times admitting maximal isometry groups larger than SO(3) are found along with their metrics, using the homothety equations and without imposing any restriction on the stress-energy tensor. It turns out that there are either II or 7 or 5 homotheties. For the space-times with SO(3) as a maximal group, solution is provided in the form of derivatives of metric coefficients, which then requires a further classification, for example, according to different types of stress-energy tensor, as has been done by Eardley [Commun. Math. Phys. 37, 287 (1974)], Cahill and Taub [Commun. Math. Phys. 21, 1 (1971)], and McIntosh [Phys. Lett. A 50, 429 (1975)]. (C) 1997 America Institute of Physics.