Lie symmetries of static spherically symmetric spacetimes by Rif tree approach

In this paper, we classify Lie symmetries of static spherically symmetric spacetimes using Rif tree approach. Instead of using direct integration techniques, we analyze the Lie symmetry equations through an algorithm developed in Maple and find all possible spherically symmetric static metrics admitting Lie symmetries. For all the obtained metrics, we provide their corresponding Lie symmetries, given by Killing, homothetic and conformal vector fields. It is found that this approach produces all the previously obtained metrics by direct integration techniques, in addition to some new physically realistic metrics.